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Improve Circuit. Unexpected Behavior.

ThomsCircuit

Well-Known Member
I put together this turn signal / brake simulator to work with another circuit. The goal is to match the cycle of flashes with my vehicle. The circuit flashes and I can adjust it however when i engage/ trip the other push buttons that simulate a left brake pedal press with a right turn signal or visa-versa or a full hazard situation pin (3) on the 555 circuit does not instantly illuminate the LED. Instead it is slow to reach full brightness and delays the relay from engaging. What can I try to make this function as it should?
Note. The green component is not being used.

turn sig sim.png
 
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It would appear that the 555 is free-running so when it goes high is random as compared to when a button is pressed.

It also appears that K1 will not do anything when the brake is applied since it is applying 12V through the turn-signal switch that is already continuously high from the brake signal.

I assume you want the tail-light to blink when both the brake and turn signal are active.
That would require some type of inhibit/logic function to block the brake signal when the turn signal is active.
 
That would require some type of inhibit/logic function to block the brake signal when the turn signal is active.
Other than the 555 free running the remainder of the circuit is manual operated. I simply press a button to create a condition output of the other two leds. For example I will press a button to let the left led flash and hold down another button to make the right led steady. That would produce a scenario of making a left turn while braking. I manipulate the other buttons to produce other conditions that would happen in a vehicle.

The purpose is to route the output of the two leds to the "Third Brake Controller" circuit. The reason is that circuit requires adjustment. That adjustment is to match the flash rate of my vehicle. This circuit allows me to simulate my vehicle from my desk.
 
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it is more evident on slower 1.5 second blinks. I was surprised to find it worked well on faster .5 second blinks
I asked why is this a problem for your simulated circuit?
 
I asked why is this a problem for your simulated circuit?
its more of a concern. I am new to this and wanted to know if I wired something incorrectly. Yes faster flash rate works well and for my simulation i will be looking for 60-120 cycles but shouldn't it work the same at any flash rate?
 
Looking back at the circuit, the 555 and relay 1 section appears to be completely free-running, so the relay should be cycling continuously?

If that is being affected by loads on the contact side or R1, then the only possibilities I can see are either a weak PSU or a wiring fault?
 
If that is being affected by loads on the contact side or R1, then the only possibilities I can see are either a weak PSU or a wiring fault?
thank you. I will try another power supply. My breadboards have weak spots as well so I'll be replacing them as well.
 
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I put together this turn signal / brake simulator to work with another circuit. The goal is to match the cycle of flashes with my vehicle. The circuit flashes and I can adjust it however when i engage/ trip the other push buttons that simulate a left brake pedal press with a right turn signal or visa-versa or a full hazard situation pin (3) on the 555 circuit does not instantly illuminate the LED. Instead it is slow to reach full brightness and delays the relay from engaging. What can I try to make this function as it should?
Note. The green component is not being used.

View attachment 146985

Shouldn't the "Turn" PB overide its corresponding "Brake" PB?
It doesn't on your schematic.
Or maybe not required for testing the DUT.
 
Shouldn't the "Turn" PB overide its corresponding "Brake" PB?
I am completely to blame here for not designing a better schematic.

But it does do what you say it should. This is because I can press one or two buttons at once to produce any scenario.
For example: I can press and hold switches 2 & 3 to simulate a left turn with your foot on the brake. Or I can just press Switch 2 to simulate a left turn without brakes for a lane change. Also just pressing switch 6 to indicates a brake pedal scenario as if to come to a complete stop or to miss hitting a cow or other farm animal. Happens a lot in my area. Then if I get a flat tire I press switch 5 to simulate a hazard condition.

This could have most likely been designed better.
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Been working on the breadboard build. Your version. Its not complete and it is challenging as I'm using one of the negative rails as a trace to connect a number of components.

20240907_170422[1].jpg
 

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