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Delay off state of MOSFET.

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DFW-Viking

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Need some help controlling two LED lamps?

I have two separate Power MOSFET circuits each controlling the on-state of a LED lamp.

The LED is on in normal state and turns off when 12 volt is applied to the open ‘terminal’.

The application is combination- running light and turn signal, i.e. both LED’s are always on and when the right turn signal is activated, the right LED turns off (in the on period).
The same happens for the left side when the left turn signal is activated.
Further, when the right turn signal is activated (LED turning off and on), the left LED is constant on.

NOW, this is what I would like to do, for the period of which one side/LED is turning off and on, turn the other side/LED off (i.e. when the left side/LED is going through the off/on sequence, the right side/LED is turned off, and comes back on when the turn signal is de-activated).

How do I interconnect the two MOSFET circuits to do this?
 
you do not need the diodes and the resistor should be between the gate and source in order to turn the fet off when the signal is high. I suspect though that you want the LED on when the input is high. to do that you need to as an inverter or use an N FET and connect the LED to +12V
 
Thanks Ubergeek63.

Actually, the LED is 'always' ON. When the input/turn signal is high the LED is off, and this is the intend with the two circuits.

The challenge is to somehow connect the two circuits to one another, so when one LED 'blinks', the other LED turns off for the whole 'blink cycle'.
 
I was hoping that I could use a capacitor to keep the MOSFET on during the signal off period, i.e. charge the capacitor during the on (+12 volt) period and then have the capacitor keep the MOSFET on during the off period. The capacitor only needs to keep the MOSFET on for 1 – 2 seconds.

Any suggestions on how to do this?
 
the funny part about that is the "only" part. 10uF gate to source. 100K, not 100 ohm pull down. diode from flash ckt AND diode from opposite lamp. unfortunately there is always a turn off delay.

Dan
 
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