Hi

Can you provide a clear explanation of the function of each button and their dependencies?

Why are there separate on/off buttons?
Or is that just your requirement?

eT

 

He wants to use the existing switches on the POD and that's how they were set up.
ON button
OFF button
Dim/Bright button that toggles.

The supplied car schematic suggests that the lights are operable with the ignition off,

By the way...

With key off the Headlight on had 10.2v, Off Button: 10.2, and High beams had 9.3

With key on Headlight had 9.9, Off had 9.9, and High Beams had 9.1

Does this change anything in designing the circuit?

which I'm posting here.

 

Hi

Can you provide a clear explanation of the function of each button and their dependencies?

Why are there separate on/off buttons?
Or is that just your requirement?

eT

Because I am utilizing the stock headlight controls. Here's an image of what they look like:

All controls are push buttons that provide a momentary ground to the solid state. When car is turned off headlights de-energize, but headlights can be turned on when car is not running. Even if the key is in the off position.

Headlights On (Square button above button with "P") : Sends momentary ground to solid to state. Low Beams are defualt
Off (Marked "Off"): Sends Momentary ground to solid state. Turns off headlights completely
High Beams (More rectangular button at the top): Provides momentary ground for solid state. If Headlights are not energized pressing the button momentarily activates high beams until button is depressed. If the Headlights are already activated, pressing the button energizes the highbeams. Pressing again de-energizes highbeams.

Best,
Alex

 

Alex:

That was a great explanation. My design would have some missing features like flash and off when the car turns off.

pressing the button momentarily activates high beams until button is depressed.

Do you mean: "pressing the button momentarily activates high beams until button is released"?

The switch could very well be a conductive elastomer. i.e. Like the KB of many remote controls. A rubber-like contact that bridges gold plated traces on the PCB.

 

Alex:

That was a great explanation. My design would have some missing features like flash and off when the car turns off.




Do you mean: "pressing the button momentarily activates high beams until button is released"?

The switch could very well be a conductive elastomer. i.e. Like the KB of many remote controls. A rubber-like contact that bridges gold plated traces on the PCB.

Yes exactly! I believe it was designed this way to be able to "flash" the brights while on the road.

Once again thank you all for the help! I have A LOT to learn

Best,
Alex

 

HI

OK...I think this is what you want. See attached.



There are two chips, A CD4013B and CD40106B. Both will need 0.1uf bypass caps across the supply pins.

 

Other notes:
a) Power and ground to the IC's don't seem to be shown on the schematic. A lot of times they are noted elsewhere.
b) There are multiple sections in the parts. I didn't see a U5. It might be called U2e in a real schematic. e.g. U2a through U2f for a hex inverter. When you layout, you re-assign to convenient sections.
c) Any unused inputs for these sorts of IC parts need to tied to ground or the supply or they tend to oscillate and die. The selection is usually done by convenience or in your case, the lowest quiescent power which is probably ground.
d) Bypass capacitors are usually ceramic and are located as close to the IC power pins as possible.

 

HI

OK...I think this is what you want. See attached.

View attachment 141228 View attachment 141229

There are two chips, A CD4013B and CD40106B. Both will need 0.1uf bypass caps across the supply pins.

Thank you so much for taking the time to do this! I'm blown away by the complexity of this and really appreciate the help.

Is there a way to clear up the clarity in the pic? I can't quite make out some of the part numbers, and I'd love to start getting parts.

Also what relays do you suggest for this application?

Best,
Alex

 

Have you checked that this circuit breaker might just be faulty causing the lights to flash on/off. Ive seen this fault in plenty of cars.

 

Hi
Here is new version but should be the final one.






1. I changed the driver transistors to mosfets.
2. Fixed the ON FF so it latches until the OFF button is pressed.
3. All caps 25v min, Resistors 1/2w,5%, IC's, mosfets, should be Hi temp version if possible.
4. Parts can be SMD but thru hole might be easier.

eT

 

Other notes:
a) Power and ground to the IC's don't seem to be shown on the schematic. A lot of times they are noted elsewhere.
b) There are multiple sections in the parts. I didn't see a U5. It might be called U2e in a real schematic. e.g. U2a through U2f for a hex inverter. When you layout, you re-assign to convenient sections.
c) Any unused inputs for these sorts of IC parts need to tied to ground or the supply or they tend to oscillate and die. The selection is usually done by convenience or in your case, the lowest quiescent power which is probably ground.
d) Bypass capacitors are usually ceramic and are located as close to the IC power pins as possible.[/QUOTE

Have you checked that this circuit breaker might just be faulty causing the lights to flash on/off. Ive seen this fault in plenty of cars.View attachment 141247

Have you checked that this circuit breaker might just be faulty causing the lights to flash on/off. Ive seen this fault in plenty of cars.View attachment 141247

Here's an image of the board itself. The circuit breaker is circled in red. When I try to run the headlights it gets VERY hot and the headlight relay begins to click to the open and closed position repeatedly.

I would love to fix the board but I don't know even know where to begin to diagnose the issue. My plan is to build the circuit that eetech posted to bypass the headlight controls, and in the meanwhile try to figure out the issue on the board. It seems as long as the headlight relays are left out everything else works fine.

 

Hi
Here is new version but should be the final one.

View attachment 141278


View attachment 141273

1. I changed the driver transistors to mosfets.
2. Fixed the ON FF so it latches until the OFF button is pressed.
3. All caps 25v min, Resistors 1/2w,5%, IC's, mosfets, should be Hi temp version if possible.
4. Parts can be SMD but thru hole might be easier.

eT

Eetech this is awesome. Do you recommend me building this on a breadboard, or should I get it made into a PCB?

 

Eetech this is awesome. Do you recommend me building this on a breadboard, or should I get it made into a PCB?

I recommend building a breadboard first. If it operates like you want, then make a PCB.

However, you might want to see if you can fix the existing module. Might save you some work.

Do you have a multimeter?

eT

 

That circuit breaker should not be getting Hot. There is either too mutch current draw ( headlight globes been changed to higher wattage) or the actual CB is faulty or poor soldering. If you look at the circuit that CB feeds power to the relay solenoids as well as the main contacts. If it starts over heating it will cause the relays to shut off then cool & activate them again. I would be very surprised if the controlling electronics are actualy faulty. To me this is just missing what is probably the most obvious fault, as the CB should not be Hot as they are a thermal switch that is auto reset. Automotive head light circuit breakers are designed to cycle on/ off in a fault condition, this is so you are not left with no headlights at all. Be it an over load or just faulty.

 

I just bought a multi meter the other day to start learning. How could I verify it is the circuit breaker?

If it is, how could I go about replacing it with something similar?

 

I just bought a multi meter the other day to start learning. How could I verify it is the circuit breaker?

If it is, how could I go about replacing it with something similar?

Hi

See if you can get the part number of the CB. Maye its on the side. Take a picture and post.

As debe mentioned, did you add any new/different lights that could have increased the current though the CB?

 

You will need an amp clamp to monitor circuit #2 (red wire) and see how many amps are going through it when the problem occurs. Do not use multimeter ammeter as it is only rated for probably 10 amps. Tell us what reading you get. I would fix the problem and not worry about alternate circuits.

 

Troubleshooting the module:

You need to do some unconventional trouble-shooting techniques. Like the voltage from F-D and F-E with high and low beam on/off.

This will give you the total voltage drop across the two relay contacts and the circuit breaker.

I too, think there may be nothing wrong with the module.

I mentioned a shorted headlight filament. I have no idea what bulbs your car uses, but I had headlights where a much higher wattage lamp was available. e.g. the H6052 (55/65W) (4.3/5A) and H6054 (35/65W)/ (2.7/5.1 A) headlamps.

I think, the logic is working. You could check that by putting a #1157 lamp in place of the headlamps or to just test the logic wire a LED and Resistor where the relay coils go. R<=(12-2.1)/30e-3. The 2.1 varies by color. 30 mA is a good high number.

These would just act as indicators.

BUT, you mentioned a few more things. The circuit breaker is HOT and replacing the module usually fixes things.

So, either the system is drawing too much current. Some posibilities are wrong lamps or bad breaker.
There are two test points on top of the breaker. You can measure the voltage drop there. Maybe there is a part number on the breaker too. The breaker is hot, so start there. Is it the breaker or something else.

Without a clamp-on ammeter, measuring the headlamp current and voltage would be harder.

You can likely build a breakout harness at the headlamp and use two of these: https://www.pololu.com/product/2452 with a 5V power supply to measure the current through each beam to see if the current is excessive.

Parts Express has automotive relays and sockets. Sockets: https://www.parts-express.com/12-vd...source=google&utm_medium=cpc&utm_campaign=pla

Relays: https://www.parts-express.com/nte-r...source=google&utm_medium=cpc&utm_campaign=pla

70 Amps is a bit high, but nonetheless. they are mounted socket down so water drains.
You could "move" those relays to the engine compartment and separately fuse each filament.

or you can re-locate the breaker and use the 10 A version of these: https://www.delcity.net/store/12V-Auto-Reset-Circuit-Breakers/p_198669.h_198847.r_IF1003

if we can't find what we're looking for.

Current and the voltage drop ACROSS the energized contacts are what you need to look at. Current can be intrusive (A shunt resistor) or use a hall effect clamp on one wire.

So, if the logic works and the lights blink, let's find out why? You have a HOT component which is the breaker and you can easily measure across 2 relay contacts and the breaker as one thing.

All it would take is the high and low beams to be on at the same time and the breaker would get hot like it's supposed to. If a bulb blew and a piece of he filament shorted that's another possible reason.

Wires, connections, breakers, relays and switches at high currents drop some voltage. The contact resistance might be <100 milli-ohms (1e-3 ohms), but it's still a resistance. We don't want to see Volts (i,e, 1 V across a contact or a breaker). 12 V across the breaker or switch may mean it's open.

When we measure anything, you have to take into account disturbances. You can't measure the voltage and the current using the same meter because measuring current generally introduces a series resistance that may or may not be negligible.

Aside: In an 82 Celica I owned, I used test probe wire on the pop-up headlights. I had the car 17 years. Current car is that old.

 

Just looking at the circuit diagram it has 4 Hi beam globes, they usualy are 60W. So there is going to be a minimum of 20Amps draw on Hi beam. The circuit breaker should be at least 30A. Just to prove the point I would wire a 30 A fuse in place of the CB & see what happens.

 

Note here: http://www.mouser.com/ds/2/645/D_1610_ENG-1109200.pdf is a datasheet for a self-reseting circuit breaker with an automotive fuse footprint. Note the 300 trips expected lifetime. It could very well be bad.