12 MS Triggers to Avoid: Managing Multiple Sclerosis Symptoms Effectively

01.04.202128.07.2023 by alexxlab

What are the common triggers for Multiple Sclerosis. How can stress affect MS symptoms. Why is heat a significant concern for people with MS. Can pregnancy and childbirth impact MS flare-ups. How do infections relate to MS symptoms. Are vaccines safe for individuals with MS. What role does vitamin D play in MS management. How does sleep quality affect MS symptoms.

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Understanding Multiple Sclerosis Triggers

Multiple sclerosis (MS) is a complex autoimmune disorder that affects the central nervous system. For individuals living with MS, certain factors can exacerbate symptoms or cause relapses. These factors are known as MS triggers. Identifying and managing these triggers is crucial for maintaining a better quality of life and reducing the frequency and severity of MS symptoms.

Can MS triggers vary from person to person? Indeed, MS triggers can be highly individual. While some triggers are common among many people with MS, others may be unique to specific individuals. This variability underscores the importance of working closely with healthcare providers to identify personal triggers and develop tailored management strategies.

The Impact of Stress on Multiple Sclerosis

Stress is a ubiquitous factor in modern life, but for those with MS, its effects can be particularly pronounced. How does stress affect MS symptoms? Excessive stress can potentially worsen existing MS symptoms and may even contribute to the onset of new ones. The relationship between stress and MS is complex, involving both physiological and psychological factors.

Are there effective ways to manage stress for MS patients? Fortunately, several stress-reduction techniques have shown promise in helping individuals with MS:

Practicing mindfulness meditation
Engaging in regular yoga sessions
Learning and applying deep breathing exercises
Participating in cognitive-behavioral therapy
Maintaining a consistent exercise routine

By incorporating these stress-management strategies into daily life, individuals with MS may be able to mitigate the impact of stress on their symptoms and overall well-being.

Heat Sensitivity in Multiple Sclerosis

Heat sensitivity, or Uhthoff’s phenomenon, is a common issue for many people with MS. Why is heat a significant concern for MS patients? Elevated temperatures can temporarily worsen MS symptoms by interfering with the transmission of nerve impulses in demyelinated neurons. This can lead to increased fatigue, vision problems, and difficulty with balance and coordination.

How can individuals with MS manage heat sensitivity? Several strategies can help:

Avoiding direct sunlight during peak hours
Using cooling vests or neck wraps
Staying hydrated with cool beverages
Utilizing air conditioning and fans
Wearing lightweight, breathable clothing
Planning outdoor activities for cooler times of day

By being proactive about heat management, individuals with MS can reduce the likelihood of heat-induced symptom exacerbations and maintain a more comfortable daily routine.

Pregnancy, Childbirth, and Multiple Sclerosis

For women with MS who are considering starting a family, understanding the relationship between pregnancy, childbirth, and MS is crucial. Does pregnancy affect MS symptoms? Interestingly, many women experience a reduction in MS symptoms during pregnancy, particularly in the second and third trimesters. This is thought to be due to the natural immunosuppressive effects of pregnancy.

However, the postpartum period can present challenges. Is there an increased risk of MS relapse after childbirth? Yes, studies have shown that approximately 20-40% of women with MS may experience a flare-up in the months following delivery. This increased risk is believed to be related to the rapid shifts in hormone levels and the stress of caring for a newborn.

What strategies can help manage MS during pregnancy and postpartum? Consider the following:

Consulting with a neurologist specializing in MS and pregnancy
Developing a comprehensive care plan for pregnancy and postpartum
Discussing medication options that are safe during pregnancy and breastfeeding
Arranging for additional support during the postpartum period
Monitoring symptoms closely and reporting any changes to healthcare providers

The Role of Infections in Multiple Sclerosis

Infections can have a significant impact on MS symptoms and disease progression. How do infections relate to MS flare-ups? Infections can trigger or exacerbate MS symptoms through several mechanisms:

Increasing systemic inflammation
Activating the immune system
Causing fever, which can worsen heat-sensitive symptoms
Contributing to fatigue and overall stress on the body

Are certain infections more problematic for MS patients? While any infection can potentially impact MS symptoms, some are of particular concern:

Urinary tract infections (UTIs)
Respiratory infections, including the flu and common cold
Herpes virus infections
Gastrointestinal infections

What preventive measures can individuals with MS take against infections? Implementing good hygiene practices, maintaining a healthy lifestyle, and staying up-to-date with recommended vaccinations are all crucial steps in infection prevention for MS patients.

Vaccinations and Multiple Sclerosis

Vaccinations play a vital role in preventing infections, but there are often questions about their safety for individuals with MS. Are vaccines safe for people with MS? In general, most vaccines are considered safe and beneficial for MS patients. However, there are some considerations to keep in mind.

Which vaccines should MS patients be cautious about? Live attenuated vaccines, which contain weakened but live pathogens, may pose a theoretical risk for individuals with compromised immune systems or those taking certain MS medications. Examples include:

Measles, mumps, and rubella (MMR) vaccine
Varicella (chickenpox) vaccine
Yellow fever vaccine
Oral polio vaccine (not commonly used in many countries)

How should MS patients approach vaccinations? It’s essential to discuss vaccination plans with both a neurologist and primary care physician. They can provide guidance on:

Which vaccines are recommended and safe based on individual circumstances
Optimal timing for vaccinations in relation to MS treatments
Potential alternatives to live vaccines when necessary
Monitoring for any adverse reactions post-vaccination

Vitamin D Deficiency and Multiple Sclerosis

Vitamin D has gained significant attention in MS research in recent years. What role does vitamin D play in MS? Vitamin D is involved in immune system regulation and may have neuroprotective properties. Some studies suggest that adequate vitamin D levels may help reduce the risk of developing MS and potentially slow disease progression in those who already have the condition.

How does vitamin D deficiency affect MS symptoms? Low vitamin D levels have been associated with:

Increased risk of relapses
Greater disability progression
More severe fatigue
Higher rates of depression in MS patients

What are the best ways for MS patients to maintain adequate vitamin D levels? Consider the following strategies:

Regular blood tests to monitor vitamin D levels
Safe sun exposure (being mindful of heat sensitivity)
Consuming vitamin D-rich foods like fatty fish, egg yolks, and fortified dairy products
Taking vitamin D supplements as recommended by a healthcare provider
Discussing the optimal vitamin D target range with a neurologist

Sleep Quality and Multiple Sclerosis

Sleep plays a crucial role in overall health and is particularly important for individuals with MS. How does sleep quality affect MS symptoms? Poor sleep can exacerbate many MS symptoms, including:

Fatigue
Cognitive difficulties
Mood disturbances
Pain perception
Overall disease activity

Why might MS patients struggle with sleep? Several factors can contribute to sleep disturbances in MS:

Neurological symptoms like muscle spasms or restless legs
Pain or discomfort
Anxiety or depression
Side effects of certain MS medications
Bladder dysfunction leading to nighttime urination

What strategies can improve sleep quality for MS patients? Consider implementing the following:

Establishing a consistent sleep schedule
Creating a cool, dark, and quiet sleep environment
Avoiding screens before bedtime
Practicing relaxation techniques before sleep
Discussing sleep issues with healthcare providers to address underlying causes
Considering cognitive-behavioral therapy for insomnia (CBT-I)

The Importance of a Holistic Approach to MS Management

Managing MS triggers effectively requires a comprehensive approach that addresses various aspects of health and lifestyle. How can individuals with MS develop a holistic management plan? Consider the following steps:

Work closely with a multidisciplinary healthcare team
Keep a detailed symptom journal to identify personal triggers
Develop strategies to manage stress, heat sensitivity, and sleep issues
Stay informed about the latest MS research and treatment options
Engage in regular physical activity as recommended by healthcare providers
Maintain a balanced, nutrient-rich diet
Build a strong support network of family, friends, and fellow MS patients
Consider joining MS support groups or patient advocacy organizations

By taking a proactive and comprehensive approach to managing MS triggers, individuals can often improve their quality of life and maintain better control over their symptoms. Remember that MS management is an ongoing process, and it’s essential to remain flexible and adaptable as new challenges and opportunities arise.

Emerging Research in MS Trigger Management

The field of MS research is constantly evolving, with new insights into trigger management emerging regularly. What are some promising areas of research in MS trigger management? Several exciting avenues are being explored:

Personalized medicine approaches to identify individual trigger profiles
Advanced neuroimaging techniques to better understand the impact of triggers on brain function
Development of novel cooling technologies for heat-sensitive individuals
Investigation of the gut microbiome’s role in MS and potential dietary interventions
Exploration of mindfulness-based interventions for stress management in MS
Research into the potential benefits of medical cannabis for symptom management

How can MS patients stay informed about the latest research developments? Consider these strategies:

Regularly consulting with healthcare providers about new treatment options
Following reputable MS organizations and research institutions on social media
Attending MS educational events and conferences when possible
Participating in clinical trials, if appropriate and recommended by healthcare providers
Joining online MS communities to share experiences and learn from others

By staying informed and engaged with the MS community, individuals can take an active role in their care and potentially benefit from the latest advancements in MS management strategies.

The Role of Technology in MS Trigger Management

Technological advancements are playing an increasingly important role in helping individuals with MS manage their triggers and symptoms. How is technology being utilized in MS care? Several innovative approaches are emerging:

Smartphone apps for symptom tracking and medication reminders
Wearable devices that monitor activity levels and provide real-time feedback
Virtual reality systems for balance training and rehabilitation
Telemedicine platforms for remote consultations with healthcare providers
Smart home devices to assist with daily tasks and energy conservation
Advanced cooling garments with precise temperature control

What are the potential benefits of incorporating technology into MS management? Technology can offer several advantages:

Improved self-monitoring and early detection of symptom changes
Enhanced communication between patients and healthcare providers
Increased accessibility to care, especially for those with mobility limitations
More personalized treatment approaches based on detailed data collection
Greater independence and quality of life through assistive technologies

As technology continues to advance, it’s likely that new tools and strategies for managing MS triggers will become available, offering hope for improved symptom control and overall well-being for individuals living with MS.

The Importance of Mental Health in MS Trigger Management

Mental health plays a crucial role in overall MS management, including the ability to cope with and mitigate triggers. How does mental health impact MS symptoms and trigger susceptibility? Mental health can influence MS in several ways:

Stress from anxiety or depression can exacerbate physical symptoms
Poor mental health may lead to neglect of self-care and trigger management strategies
Cognitive symptoms of MS can contribute to mental health challenges
The emotional toll of living with a chronic illness can impact overall well-being

What strategies can help MS patients maintain good mental health? Consider the following approaches:

Seeking professional mental health support, such as counseling or psychotherapy
Practicing mindfulness and relaxation techniques
Engaging in regular physical activity, which can boost mood and reduce stress
Maintaining social connections and participating in support groups
Exploring creative outlets as a form of emotional expression and stress relief
Considering cognitive rehabilitation to address MS-related cognitive challenges

By prioritizing mental health alongside physical health, individuals with MS can develop a more robust and comprehensive approach to managing their condition and its associated triggers.

12 MS Triggers to Avoid: Stress, Heat, and More

Multiple sclerosis (MS) triggers include anything that worsens your symptoms or causes a relapse. You can often avoid MS triggers by simply knowing what they are and trying to sidestep them. If you can’t avoid certain triggers, you may find other approaches helpful, including a healthy lifestyle, regular exercise, and a balanced diet.

Just as no two people will have the same experience with MS, no two people will likely have the same MS triggers. You may have some triggers in common with others who have MS, as well as some that are unique to you.

Over time, you and your doctor may be able to identify triggers that make your symptoms worse. Keeping a journal of your symptoms, when they occur, and what you were doing beforehand can help you identify potential triggers.

Here are some of the most common triggers you may experience with MS and tips to avoid them.

Having a chronic disease like MS can establish a new source of stress. But stress can stem from other sources, including work, personal relationships, or financial worries. Too much stress may worsen your MS symptoms.

How to avoid: Find a relaxing, stress-reducing activity that you enjoy. Yoga, meditation, and breathing exercises are all practices that may help reduce stress and eliminate the risk of making symptoms worse.

The heat from the sun, as well as artificially heated saunas and hot tubs, may be too intense for people with MS. They can often lead to a period of exacerbated symptoms.

How to avoid: Skip high-heat environments like saunas, hot yoga studios, and hot tubs. Keep your home cool and run extra fans if necessary. On hot days, avoid direct sunlight, wear loose, light-colored clothes, and stay in the shade as much as possible.

Pregnant people with MS may experience a relapse after delivering their baby. About 20 to 40 percent of women may have a flare-up in the period just after giving birth.

How to avoid: You may not be able to prevent a flare after childbirth, but you can take steps to reduce its severity and impact. In the immediate days after giving birth, let friends and family members help you with your new baby so that you can get rest and care for yourself. This will help your body recover more efficiently.

According to limited research, breastfeeding may have a potential protective effect against postpartum flare-ups, but the evidence isn’t clear. If you’re taking disease-modifying medication, you may be unable to breastfeed. Talk with your OB-GYN and neurologist about your post-birth options.

Infections can cause MS flare-ups, and MS is also more likely to cause certain types of infection. For example, people with reduced bladder function are more likely to develop urinary tract infections. The infection may exacerbate other MS symptoms. Infections like the flu or common cold can worsen MS symptoms.

How to avoid: A healthy lifestyle is an important part of treatment for MS. Plus, it helps prevent other diseases and infections. Wash your hands during cold and flu season. Avoid people who are ill when you’re experiencing a flare. See your doctor if you think you’re getting sick.

Vaccines are generally safe — and recommended — for people with MS. Certain vaccines that contain live pathogens can potentially exacerbate symptoms. If you’re experiencing a relapse or taking certain medications, your doctor may also recommend you postpone vaccination.

How to avoid: Talk with your neurologist about any vaccine you’re considering. Some vaccines, like the flu vaccine, may help you prevent a future flare-up. Your doctor can help you determine which are safest for you.

One study found that people with lower vitamin D levels have a higher risk of flare-ups than those with adequate vitamin D levels. There is increasing evidence that vitamin D can protect against developing MS. Still, more research on how this vitamin affects the disease course is needed.

How to avoid: To help prevent this, your doctor may monitor your vitamin D levels regularly. Supplements, food, and safe sun exposure may help. Be sure to talk with your doctor about your safest supplement options before trying any.

Sleep is vital for your health. Your body uses sleep as an opportunity to repair your brain and heal other areas of damage. If you aren’t getting enough sleep, your body doesn’t have this downtime. Excess fatigue can trigger symptoms or make them worse.

MS can also make sleep more difficult and less restful. Muscle spasms, pain, and tingling may make it difficult to fall asleep. Some common MS medications may also interrupt your sleep cycle, preventing you from getting shut-eye when you feel tired.

How to avoid: Talk with your doctor about any sleep problems you may have. Sleep is vital to your overall health, so this is an important area of treatment and observation for your doctor. They can rule out other conditions and give you tips for managing fatigue.

A balanced diet and regular exercise can go a long way to helping you avoid a flare-up and ease MS symptoms. A diet high in processed foods is unlikely to provide you with the high quality nutrition it needs.

How to avoid: Work with a dietitian to develop an eating plan you can stick to. Focus on good sources of protein, healthy fats, and carbohydrates. While research isn’t yet clear on the best diet for people with MS, studies do suggest eating healthy foods can have a positive effect.

Cigarettes and other tobacco products can increase your symptoms and make progression happen more quickly. Likewise, smoking is a risk factor for several medical conditions that can worsen your overall health, including lung disease and heart disease.

One study found that tobacco smoking is associated with more severe MS. It also may speed up disability and disease progression.

How to avoid: Quitting smoking, even after your diagnosis, can improve your outcome with MS. If you smoke, talk with your doctor about effective smoking cessation options.

Certain medications have the potential to worsen your MS symptoms. Your neurologist will work closely with all of your doctors to make sure you don’t take medications that may trigger a flare-up.

At the same time, your neurologist may closely watch the number of medications you’re taking. Medications can interact with one another, which can cause side effects. These side effects could trigger an MS relapse or make symptoms worse.

How to avoid: Report all medications you take to your doctor, including supplements and over-the-counter drugs. They can help you narrow down your list to the necessities so you can prevent problems.

Sometimes, MS medications can cause side effects. They may also not seem as effective as you’d hope. But this doesn’t mean you should stop taking the medications without your doctor’s approval. Stopping them can increase your risk of flare-ups or relapses.

How to avoid: Don’t stop taking your medications without talking with your doctor. Though you may not realize it, these treatments are often working to prevent damage, reduce relapses, and stop new lesion development.

Fatigue is a common symptom of MS. If you have MS and push yourself to go without sleep or overexert yourself physically or mentally, you may experience flare-ups. Exertion and fatigue can trigger a relapse or make flares last longer.

How to avoid: Take it easy on yourself and listen to your body’s cues. Slow down when you’re feeling tired. Rest as long as you have to. Pushing yourself to the point of exhaustion will only make recovery more difficult.

When you have MS, you may need to make a few lifestyle changes to prevent relapses and reduce your symptoms. You may be able to easily avoid some triggers, but others may require more work. Talk with your doctor if you’re having difficulty managing your MS symptoms.

Symptoms, Triggers, Prevention, and Treatment

Written by WebMD Editorial Contributors

Medically Reviewed by Jabeen Begum, MD on February 23, 2023

MS Flare-Up
What Are the Symptoms of a Flare-Up?
What Causes Flare-Ups?
How to Prevent Flare-Ups
Ways to Treat a Flare-Up
What to Do After a Flare-Up
More

If you feel fine for weeks or months but then your multiple sclerosis (MS) symptoms happen again, you probably have what doctors call a relapse or flare-up. The good news is there are ways to treat or prevent them.

Everyone’s flare-ups are different. Some are mild. Others are severe.

During a flare-up, you may have new symptoms or symptoms you already may get worse.

You may have one or more of these:

Balance problems
Blurred vision or blindness in one eye
Dizziness
Numbness
Pain
Pins-and-needles feeling
Tiredness
Weakness

They can happen when inflammation in your nervous system damages the layer that covers and protects your nerve cells. This slows or stops nerve cell signals from getting to the parts of your body where they need to go.

If you have relapsing-remitting MS, you may have flare-ups followed by symptom-free periods called remissions. To be a true relapse, your symptoms must start at least 30 days after your last flare-up and stick around for at least 24 hours.

The exact mechanism that leads to a relapse is unknown, but it’s thought to be related to an increased overall immune response. There’s some evidence that systemic infection (viral or bacterial), postpartum period, stress, and assisted reproduction (infertility treatment) can be associated with a flare-up. That can lead to more brain cell damage and demyelination.

MS flare-ups are different from pseudo-flares. Those are a temporary worsening of symptoms brought on by external factors. Unlike flare-ups, pseudo-flares aren’t linked to new damage from your MS. They usually last less than 24 hours. Typical triggers for pseudo-flares include high body temperature from fever, infection, too much exercise, or activity; getting your period; new medications; and stress. Usually, removing the underlying stressor can help resolve a pseudo-flare.

But it can be hard to tell the difference between flare-ups and pseudo-flares, so talk to your doctor about any new or worsening symptoms.

MS flare-ups can be caused by:

Smoking
Infections
Eating poorly
Heat
Skipping medication
Stress
Lack of sleep

To try to prevent a flare-up from happening:

Take meds as directed. The drugs your doctor prescribes help slow your MS from getting worse and help prevent relapses. If you have side effects, don’t just stop taking them. One study found about 25% of MS patients who stopped taking their meds had a relapse. Certain meds for Crohn’s disease or rheumatoid arthritis may cause MS-like symptoms. So can drug interactions. Check with your doctor to see if there are meds you’re taking that could be interacting with one another, and if your current meds are right for you.

Stay healthy. A bout of cold or flu can set off your MS symptoms. A bladder infection can trigger either a flare or a pseudo-flare, so the same advice applies. In fact, infections cause a third of MS flare-ups. Wash your hands with warm water and soap during the day, get your yearly flu shot, and avoid people who look sick. Stay hydrated. Try to avoid anyone who is sick. Make sure your food is cooked properly. Practice safe sex.Ask your doctor for other ways to avoid bladder infections, including vaccinations. Try to avoid anyone who is sick. Make sure your food is cooked properly. Practice safe sex.

Relax. In some people with MS, stress can bring on flare-ups. Find calmness with meditation, yoga, counseling, or anything else that’s good for you and helps you unwind. In one study, MS patients reported their stress level was cut nearly in half after 6 weeks of yoga.

Rest. You won’t feel well when you’re worn out. Sleep problems are common in people with MS. Symptoms like pain and muscle spasms can keep you up at night. Some of the meds that treat MS interrupt sleep, too. Work with your doctor to get your symptoms under control so you can sleep. Adjust your meds if they keep you awake. Aim for 7 to 8 hours of sleep per night.

Stay cool. High temps may trigger a flare-up. If you’re affected negatively by warm surroundings, you should skip saunas, hot tubs, and hot showers and baths. Most of the time hot weather causes fatigue. Also, do what you can to avoid being outdoors on hot days. Take cool baths and/or run air conditioning. Try a hat or clothes that hold ice packs or frozen gel packs to stay comfortable. If you have an exercise goal, divide the time you exercise into smaller segments, with rest after each one.

Eat well. Eat foods rich in omega-3 fatty acids. They’re believed to fight inflammation. Also, get plenty of fiber and stay away from foods with saturated and trans fats. A healthy diet helps keep your immune system strong.

Steer clear of smoking. This is a major risk factor for flare-ups, and it can make your symptoms worse. If you smoke, your doctor can help you make a plan to stop.

Your symptoms might go away on their own if they’re mild. Even so, let your doctor know what’s going on.

Treating symptoms can shorten your flare-ups and help you recover faster. The goal is to bring down the inflammation that caused your symptoms.

Your doctor will likely prescribe a steroid drug. Steroids curb inflammation and can help you get over a relapse faster. But they can’t undo the damage that’s been done or slow your disease. Methylprednisolone is the most common steroid used for this. You might take it as tablets or get it through an IV in a hospital or your doctor’s office.

Some people can’t take steroids. Others are bothered by side effects, which include weight gain, mood changes, trouble sleeping, and upset stomach. Another option may be ACTH gel (Acthar gel). It’s injected into your muscle or under your skin. It triggers your adrenal gland to release hormones that bring down inflammation.

For a severe flare-up that doesn’t get better with steroids, you might try plasma exchange. First, a health care professional will take some of your blood. The liquid part, called plasma, is taken out. It’s replaced with a substitute plasma fluid or with plasma from a donor. Then, the blood is returned to your body. Talk to your doctor about whether this would help you.

You can also treat a flare-up by using the same tips in the section above for preventing them. For instance, get plenty of rest and make sure to eat well.

You can recover fully after a relapse, but it might take weeks or months to get over all your symptoms. If you had a lot of nerve damage, some symptoms might not fully go away.

You may need extra help to get back to your normal life. A rehab program can put you back on track. Your rehab team will help you with:

Exercise
Speech
Dressing and personal care
Movement
Home chores
Problems with thinking and memory

If you also see a neurologist (a doctor who specializes in problems with your brain, spinal cord, or nerves) for your MS, let them know about your flare-up. It could affect which meds they prescribe for you.

Top Picks

50.

Ms trigger.

MS trigger
is a synchronous two-stage
trigger with static
management. Schematically it
is executed on two flip-flops: M(master –
main) and S(slave –
auxiliary). M-trigger perceives
input information, and S-trigger
captures the state of the trigger as a whole.
In this case, both triggers can be
the same type, for example RS-
or D flip-flops,
or different. Control link between
M-trigger and S-trigger
carried out by two synchronization series, or
by means of a inhibiting inverter.
Scheme of a synchronous two-stage RS flip-flop
with static control, performed
according to the MS-trigger scheme,
where as an M-trigger
and S-flip-flop is used
synchronous static RS flip-flop looks like this
way:

D-trigger
has one information input (D-input)
and input for synchronizing
impulse (Fig. 2.4). Main
assigning a D flip-flop
is the delay of the signal applied to the input.
Like an RS flip-flop, it can be built
on different logic elements.
It can be seen that at С = 0 the change in the input
the signal does not affect the state
trigger, and only when C = 1 trigger
takes on a state determined by
input signal.

Variety
D-flip-flop is a DV-flip-flop that
in addition to the D-input has a control
V-inlet (in Fig. 2.4, to shown
dotted line). With V = 1 trigger
works similarly to a D-trigger,
and for V =
0 keeps initial state regardless
from a signal change at the D-input
and C-entrance.

wide
application in construction practice
digital devices find D-flip-flops
with dynamic control (155TM2 564TM2).
They respond to information signals
only when the signal changes to
C-input 0 to 1 (direct dynamic
input) or 1 to 0 (inverted dynamic
entrance).

Fig.
2.4. D-trigger (DV-trigger if available)
V-input): and –
functional diagram; b –
state table; to –
symbol; –
timing diagrams

functional
D flip-flop circuit
with direct dynamic control (Fig.
2.5) consists of three asynchronous RS triggers.
Two of them, built on elements 1,
2 and 3, 4 are called commuting, and the third
– on
elements 5, 6 are output. Signals on
switching trigger outputs
control the state of the output trigger.

At
signal C = 0 at the outputs q2 and q3 is formed
neutral for output trigger
combination and it is in mode
storage. Change of information
signal during this period of time causes
signal change at outputs q ₄ and
q ₁ .
Elements 2, 3 are ready to accept these
signals as soon as permission appears
signal C = 1. At the time of its appearance
the levels at the outputs q2 and q3 change and
set the output trigger to new
state corresponding to the information
signal at the D-input in the previous cycle.

If
information signal change
will occur during the establishment
states of the output trigger, switching
triggers won’t miss it because
zero level at the output of element 2
blocks the inputs of elements 1 and 3. Thus
Thus, the appointment of switching
triggers is to receive information,
passing it to the output trigger at the moment
signal drop at the C-input from 0 to 1 and
implementation from that moment
self-locking against impact
information signal.

Trigger
dynamic control is not possible
call it two-stage in accepted m
earlier sense, since it does not have that
push-pull transmission mechanism
information from inputs to outputs
is clearly expressed in
two stage trigger. Therefore, in
convention for such triggers
one letter T is provided.

D flip-flop
with dynamic control can be
used as a T-trigger, for
it needs information input
D connect with inverted output (fig.
2.5, g ).

Fig.
2.5. D flip-flop
with dynamic control: a
– functional
scheme; b
– temporary
diagrams;
in
– conditional
designation; g
– conversion
in T-trigger

T-trigger
(flip-flop with even input T) is
flip-flop with one input that changes its
state with the arrival of each input
impulse.

At
implementation of the T-trigger on potential
logical elements in the basis can
be put a two-stage RS flip-flop,
because it provides the required
for the operation of the T-flip-flop, the delay in transmission
information from inputs to outputs; C-entrance
acts as a T-input, and S-
And
R inputs must be connected
cross-feedback with
trigger outputs (Fig. 2.6).

Fig.
2.6. T-trigger (TV-trigger
with V-inlet): a
– functional
scheme; b
– conditional
designations; in
– table
states

Variety
T-trigger is a TV trigger having
additional control input V (on
rice. 2.6, and shown
dotted line). With a signal V = 1 TV-trigger
works according to the rules of the T-trigger.
With signal V =
0 trigger saves its state
unchanged.