No, that is supposed to be the output of the DRL circuit i need. The top line is the output from the car's controller to the bulbs. Add the DRL circuit output together with the output from the car's controller, then the last line is representing these combined, resulting in a DRL function at the start and end, and a in-sync flashing when blinking.The picture in post #11, what is the "blinker circuit"? Is that a signal that stays low while the bulbs are blinking, then goes normally high? Is it available as an input?
What signals are available as inputs to the new circuit?
See if this will work for youNo, that is supposed to be the output of the DRL circuit i need. The top line is the output from the car's controller to the bulbs. Add the DRL circuit output together with the output from the car's controller, then the last line is representing these combined, resulting in a DRL function at the start and end, and a in-sync flashing when blinking.
I think that main difference between your circuit's function and the one #21 is, yours has a faster turn-on after the turn signal pulses stop, which may be noticeable as a slightly slower turn-on of the lamp..See if this will work for you
Yup. I mentioned to the TS there would be more complexity...I think that main difference between your circuit's function and the one #21 is, yours has a faster turn-on after the turn signal pulses stop, which may be noticeable as a slightly slower turn-on of the lamp..
The TS will have to decide if the added complexity is worth a quicker turn-on.
D3 and D4 are reverse voltage protection diodes. The operating current through them should be about the same D1 and D2 with the exception of a few additional milliamps (circuit operating current) thru D3 and D4. I think the TS mentioned 500mA for each bulb...Just a small concern.
D3 and D4 should likely be higher current rated diodes since the bulb current goes through them when the blinkers are off.
(What is their purpose?)
Okay.I think the TS mentioned 500mA for each bulb.
Let's say i want to dim the DRL function, would that be possible via a potentiometer between the 555 out and 555 vcc rail?See if this will work for you
Each circuit uses a 555 Timer configured as a Missing Pulse Detector to detect the blinker signal.
If the blinking signal is present, the timer output is high, and will allow the front bulb to follow the Blink signal.
If the blinking signal is absent, the timer output is low, and will override the blinking signal and light the front bulb steady on.
The simulation graph shows that the bulbs will flash in unison (synchronized).
I think you can make two circuits compact enough to fit where you need them.
View attachment 224250
View attachment 224162
Yes, you could put a resistor in series with the MOSFET outputs to the lamps in the 555 circuit.Let's say i want to dim the DRL function, would that be possible via a potentiometer between the 555 out and 555 vcc rail?
Probably a stupid question, but is it not possible to have a resistor divider on the "lout" rail to pull the gate voltage a little higher on the mosfet? Would that not limit the S-D current of the mosfet?Yes, you could put a resistor in series with the MOSFET outputs to the lamps in the 555 circuit.
But a pot would need to have a power rating sufficient to carry the current of the lamp.
Likely better just to experimentally determine the value for a fixed resistor.
If you put a series resistance or gate divider, it would dim the front bulb, but there would be inconsistent brightness between blink and steady brightness levels. Why would you want to dim DRL lights?Probably a stupid question, but is it not possible to have a resistor divider on the "lout" rail to pull the gate voltage a little higher on the mosfet? Would that not limit the S-D current of the mosfet?
The lights are quite bright, so to have the option to dim them to say 70% would be "nice to have" yes, there would be a difference between the blinking and drl function, but i don't mind that. Anyway, i just woundered if it was possible to regulate the mosfet using that method. Most likely not. Maybe it would be hard to match both side's brightness levels anyways. The bulbs are each 27w 1.93A according to what i find online (not able to check due to work). I have tried to make a pcb in easyeda (my first time making a pcb). I used a irf9530, hopefully that's going to work!If you put a series resistance or gate divider, it would dim the front bulb, but there would be inconsistent brightness between blink and steady brightness levels. Why would you want to dim DRL lights?
Yes, that should work fine.I used a irf9530, hopefully that's going to work!
Yes in theory, but in practice the current is very sensitive to Vgs in the active region and can vary significantly with temperature and supply voltage, so it's not really a practical way to regulate the current.is it not possible to have a resistor divider on the "lout" rail to pull the gate voltage a little higher on the mosfet?
Q4 is connected wrong. emitter should connect to R7, collector to ground.View attachment 230014i
I have made the circuit according to the schematic above, but i have some issues. The output is high at power up, but when pulsed on the "in" input, the output goes low and does not recover. Where have i messed up?
by Jake Hertz
by Jake Hertz
by Jake Hertz