Fire alarm system may be having some electronic devices and cards, in which some capacitors are used. Capacitors are part of any electronic cards.
Capacitors store charge. There are many applications for their use. There is no set amount of capacitors in a circuit since it is application dependent.
to protect a circuit from damaging
A thyristor is a part of a alarm circuit you use it so the alarm stays on
there is no separate capacitors for AC and DC. All capacitors are same. Electrolytic capacitors are manufactured by creating a die-electric by chemical etching or electroplating on one plate. Such capacitors when connected in AC circuit dislodges the die-electric material and thus results in short circuit between the two parallel plates of the capacitor. For AC circuits only non-electrolytic capacitors should be used. The common type is oil impregnated paper capacitor.
the Colpitts oscillator , named after the inventor of the circuit , is characterised by the use of Two Capacitors in series which are then connected in parallel across the inductor of the resonant circuit for obtaining the required frequency. The junction of the two capacitors is used for the positive feedback used for generating the oscillations. This circuit is used for High frequency oscillators , mainly due to ease of obtaining required ratio of the two capacitor values as per the circuit design. Also the two capacitors in series reduces their total equivalent value , which is not a problem as in HF circuits as the values and size is comparatively low. For information , a corresponding Low frequency circuit is called a Hartley oscillator , also named after its inventor. This uses a tapped inductor & one capacitor for the resonant circuit, since it is more easier to fabricate large value tapped inductors , than to use two bulky ( since the value of capacitors in series is reduced ) capacitors necessary for the equivalent Colpitts oscillator.
You can use a PNP or an NPN transistor in a fire alarm circuit. Both will work. It all depends on how you want to energize the alarm, and with what polarity of signal.
Capacitors store charge. There are many applications for their use. There is no set amount of capacitors in a circuit since it is application dependent.
to protect a circuit from damaging
because their effects are desired to make the circuit work
A thyristor is a part of a alarm circuit you use it so the alarm stays on
to limit the current and to use it as a back up battery capacitors are used ..
To effectively shut off a fire alarm, locate the alarm panel and enter the code or use a key to silence the alarm. If you cannot do this, contact the fire department for assistance.
fire alarm
It means 'End Of Line'. In a fire alarm system (usually conventional systems use this technique) a resistor is placed at the very end of the fire alarm circuit at the last device. This device could be a Manual Call point, Sounder, Bell Smoke/Heat detector, strobe etc. This then enables the panel to monitor the circuit. For example, if the resistor is moved or disconnected, then it will show up as a fault on the panel, giving indication the something has gone wrong in the system and that it needs to be fixed. Not all EOL's are resistors though. They can also be capacitors or diodes from what we know.
I wanna use resistor , capacitor and amplifier 7173 for switch alarm circuit. How can i choice resistor and capacitor value because i wanna use 24V DC.
parker
It is illegal and dangerous to disable a fire alarm system. If you need to temporarily silence a false alarm, use the reset button or contact the building management for assistance.