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Stairs light Timer

am.steen

Jul 10, 2023
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I design and built this circuit and it some time works and other time nothe circuit consists of three parts first one detect ac then fire the c005 timer and the timer fires optocoupler which connects triac and ac load ( lamps ).
Now after put every thing in small box when connect power the lights light direct without trigger the timer and continue lighting forever one notice. I power the circuit from 5v charger not from transformer as in diagram
Screenshot_20230818_135444_WhatsApp.jpg
 
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Harald Kapp

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A few issues:
  1. your 5 V supply is not a stable 5 V. It will be superimposed with a comparatively high 100 H7 (or 120 Hz) ripple. The zener diode can limit the voltage to no more than 5 V (plus some), but it will do nothing against the voltage dropping below 5 V. Insert a simple 5 V regulator, e.g. 7805 or 78M05.
  2. What is the reason for the trigger circuit around D11, U2 and associated components? All it does is to force the collector of U2 to GND whne the bushbutton is pressed. You can achieve the same effect with les components and much higher safety by remocing the trigger circuit and placing the pushbotton instead of U2, like so:
    1692357518294.png
  3. Check your wiring. Keep the high voltage parts and the low voltage parts as separate as possible.

Observe safety precautions, you're dealing with potentially lethal voltages and currents in this circuit. DIsconnect from mains before handling any part of the circuit.
 

am.steen

Jul 10, 2023
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A few issues:
  1. your 5 V supply is not a stable 5 V. It will be superimposed with a comparatively high 100 H7 (or 120 Hz) ripple. The zener diode can limit the voltage to no more than 5 V (plus some), but it will do nothing against the voltage dropping below 5 V. Insert a simple 5 V regulator, e.g. 7805 or 78M05.
  2. What is the reason for the trigger circuit around D11, U2 and associated components? All it does is to force the collector of U2 to GND whne the bushbutton is pressed. You can achieve the same effect with les components and much higher safety by remocing the trigger circuit and placing the pushbotton instead of U2, like so:
    View attachment 60298
  3. Check your wiring. Keep the high voltage parts and the low voltage parts as separate as possible.

Observe safety precautions, you're dealing with potentially lethal voltages and currents in this circuit. DIsconnect from mains before handling any part of the circuit.
Thanks for your replay
1. I use the trigger part to trigger the timer from normal ac buttons in each floor.
2. I use 5v mobile charger in my real circuit but in proteus there is no power supply.
 

kellys_eye

Jun 25, 2010
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Makes me wonder - what happened to those plain, simple, reliable pneumatic stair light controllers.....

 

Harald Kapp

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1. I use the trigger part to trigger the timer from normal ac buttons in each floor.
With C1 = 1 µF there is still serious ripple on the LED current:
1692465511477.png
Make this 100 µF to reduce the ripple noticeably:


2. I use 5v mobile charger in my real circuit but in proteus there is no power supply.
Use an 7805 for a stable 5 V supply, see e.g. here.

- What's the use of R1 || R5? Why not use 1 × 4.7 kOhm?

- Add a bleeder resistor from U3 pin 3 to pin 1. 47 kOhm should be good. This will ensure that the gate of the thyristor/SCR is definitely at 0 V when the lights should be off. Any capacitive coupling into the gate is greatly reduced by this resistor.
 

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Bluejets

Oct 5, 2014
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Looks dangerous to me....no fuses.....mains wiring to mains operated stair light....wow...!!
Then there is all this so called control gear...tucked away in a wall cavity no doubt..?

These days with so many low voltage LED alternatives........
 
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