Component input for changing a ground path in a circuit

Thread Starter

fergyz

Joined Jan 15, 2017
3
There may be a simple answer but after a long day, my brain is fried. i need input on a PCB friendly component best suited for switching between ground circuits.

input/operating voltage:
Primary circuit - 11-14.4v
Secondary circuit input - 11-14.4v

Primary circuit powers the LED at full brightness

Secondary circuit changes the ground path to apply an additional resistence. the intent is to reduce brightness by 50-75% during low/no-light conditions. The resistor value for the secondary circuit will be determined before final installation. this requires end user (in person) to provide "brightness" input.

In short, i need a component to switch ground paths when the secondary input voltage is applied to it. A mechanical switch is not feisable solution for this part of the circuit (PCB).

I will be using a magnetic switch to apply the chassis ground to the overall circuit. The total assembly will be covered with a plate and this was the easist way to keep the circuit inactive while the cover was in place.

I value your input. Thanks2017-01-19_13-31-37.png
 

#12

Joined Nov 30, 2010
18,159
This really isn't clear. If you want two brightnesses, just have one power source turn on a transistor that shorts out one of the resistors. No need to mess with ground.
 

Thread Starter

fergyz

Joined Jan 15, 2017
3
I appreciate the input. I am aware of a couple of ways I can control the high/power side. I know it looks unconventional but I am still after controlling the ground side only. I do not want to use a standard automotive SPDT switch or relay.
 
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