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Someone please help clicking relay

Minder

Apr 24, 2015
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It is unusual, but it appears that BEMF diodes are not fitted to the relays , which means you would need to place the meter across the relay coils themselves, on the reverse side of the board.
M.
 

elebish

Aug 16, 2013
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Aug 16, 2013
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Minder here is a picture of the board in question can you please point out which one is a diodeView attachment 26505

One end of the diode must be removed to check the forward voltage drop across the diode. The purpose of that diode is to block the reverse magnetic field from briefly re-energizing the coil. You'll need an ohmmeter with a diode check mode to check the diode. Typically, you'll read about .6 volts with the neg lead on the banded end of the diode.
 

Minder

Apr 24, 2015
3,475
Joined
Apr 24, 2015
Messages
3,475
One end of the diode must be removed to check the forward voltage drop across the diode. The purpose of that diode is to block the reverse magnetic field from briefly re-energizing the coil. You'll need an ohmmeter with a diode check mode to check the diode. Typically, you'll read about .6 volts with the neg lead on the banded end of the diode.

It was intended to check to see if the full voltage is across the coil or intermittent, not to check the diode, it is just a convenient place to check the voltage across the coil without accessing the bottom of the board.
The diode is normally used to suppress any H.V. BEMF .
M.
 
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