This document discusses several industrial control circuits that use thyristors like TRIACs, DIACs, and SCRs. It describes how TRIACs can be used to control the speed of a fan or dim lights by varying the resistance and thus the firing time of the thyristor. Battery chargers and emergency lighting systems that use SCRs are also summarized. Temperature controllers, electronic timers, low power DC flashers, and uninterrupted power supplies are briefly explained in terms of thyristor operation.

1. Unit 6
Industrial Control Circuits
Presented By :
Ashish Sadavarti

2. SPEED CONTROL OF FAN USING TRIAC

4. If R Increases -> Current Decreases-> C charge slowly->
SO DIAC ON Late-> so TRIAC ON Late
(LESS VOLTAGE get to the FAN so fan SPEED DECREASES )
If R Decreases -> Current Increases-> C charge fast->
SO DIAC ON fast-> so TRIAC ON fast
(MORE VOLTAGE get to the FAN so fan SPEED INCREASES )

5. LIGHT Dimmer CIRCUIT
USING DIAC-TRIAC

7. If R Increases -> Current Decreases-> C charge slowly->
SO DIAC ON Late-> so TRIAC ON Late
(LESS VOLTAGE get to the LAMP DIM OR LIGHT)
If R Decreases -> Current Increases-> C charge fast->
SO DIAC ON fast-> so TRIAC ON fast
(MORE VOLTAGE get to the LAMP BRIGHT)

8. BATTERY CHARGER USING SCR

9. D ON

10. EMERGENCY LIGHTING SYSTEM

11. Current (1)->When power supply available then Lamp ON
by full wave Rectifier.
Current (2)-> at the Same time Battery Charge by
second current.

12. Current ->when power supply not available
then lamp on by Battery through SCR.

13. TEMPERATURE CONTROLLER
USING SCR

14. Current-> IN THIS,SCR ON….. SO HEATER ON,
SO TEMPERATURE OF MERCURY In POT INCREASES &
It EXPAND.

15. No Current-> IN THIS,SCR off….. SO HEATER off,
Because In POT mercury expand so short A & B
terminals(gate cathode terminal of SCR) .

16. ELECTRONIC TIMER USING SCR

17. Current -> If switch close, So Capacitor ‘C’ Charge.

18. • If R2 Increases ->current Decreases-> C charge slowly->
SO UJT ON late-> so SCR ON late
(More Time required for turn on the SCR)
• If R2 Decreases -> current Increases-> C charge fast->
SO UJT ON fast-> so SCR ON fast
(Less Time required for turn on the SCR)

19. LOW POWER DC FLASHER

20. Initially Trigger pulse given to SCR1. So SCR1 ON.
Because current (1)-> Lamp ON
Because current (2)-> Capacitor C1 charge of given
polarity.

21. 1) When capacitor C1 full charge then + signal given to
SCR2(anode) & gate signal given to SCR 2. so SCR2 ON.
2) Due to that,negative(reverse) voltage on anode of
SCR1. so SCR 1 off ,SO Lamp also off.
+

22. UNINTERRUPTED POWER SUPPLY
(UPS)

25. SWITCH MODE POWER SUPPLY(SMPS)

26. SWITCH MODE POWER SUPPLY(SMPS)

27. Thank You