I have a circuit with an LED in it that occasionally blows out.For a long time I didn't have any idea what might be causing this, but recently I found that the power supply that this circuit is designed to "piggy back" off of, has a rather large AC powered coil (inductor) that is shut on and off via a mechanical switch. I noticed that the "spike" caused by this was barely visible on the ocilliscope, and was very short in duration, but high in voltage. Since the circuit that is controlling the LEDs in it has a 12volt DC regulator, I tried a 14 Volt MOV across the positive and negative terminals of the Voltage Regulator, but the spikes were still visible, and appeared to be still well over 20 volts negative and positive. I tried to put a diode across the load (LED)with the black band toward positive, but after that I noticed the spikes were still visible, but they were only positive going, and the LED went out. I can see the LED go very bright for an instant as the coil is turned off so I'm wondering if that's what's causing my LEDs to go out. The 24 volt coil that I think might be causing the problem cannot be removed, so I'm wondering if there's a "local"way to protect my LED?.
Thanks again for all the past help,
Rich
Thanks again for all the past help,
Rich