Need Circuit Diagram for "Whirlpool L1961 Quartz pp6" washing machine PCB.

[rakshitarya]

Need Circuit Diagram for "Whirlpool L1961 Quartz pp6" washing machine PCB.
In the power Supply of this, 4 12vDC Relay is used with the four Zener Diode.
Want to know the Zener Voltage/Rating for these zener diodes as diode is burned up on PCB and no number is visible on the diodes.

 

[KlausST]

Re: Need Circuit Diagram for "Whirlpool L1961 Quartz pp6" washing machine PCB.

Hi,

How do you know that these are zener diodes.

Usally in combination with relays one uses standard (non zener) diodes as freewheeling diodes.
Freewheeling diode: When the diode rating (voltage, current) is same or higher than the coil rating then you should be on the safe side.
Nothing special needed.

Klaus

 

[BradtheRad]

Re: Need Circuit Diagram for "Whirlpool L1961 Quartz pp6" washing machine PCB.

Are they plain diodes or zener type? With a relay it is common advice to install a plain diode across the coil, to absorb shutoff spikes.

Or if it really is a zener, then its purpose could be to limit voltage to the relay coil so it never goes above 12 or 13V. Conceivably a zener could get burned in that case.
The size of a diode usually tells you about its watt rating. If you replace burned ones then it may be a good idea to use a higher W rating.

 

[rakshitarya]

Re: Need Circuit Diagram for "Whirlpool L1961 Quartz pp6" washing machine PCB.

Hi,

How do you know that these are zener diodes.

Usally in combination with relays one uses standard (non zener) diodes as freewheeling diodes.
Freewheeling diode: When the diode rating (voltage, current) is same or higher than the coil rating then you should be on the safe side.
Nothing special needed.

Klaus

Hi KlausST,

thnks for your prompt reply, i am attaching the PCB image.
I checked the zener diode rating with the 24 v battery and 2.2 k resistor in series with diode. but i am clueless and i think its high voltage zener diode.
please share your opinion in this regards

 

[rakshitarya]

Re: Need Circuit Diagram for "Whirlpool L1961 Quartz pp6" washing machine PCB.

Hi All,
Thanks for your prompt response toward the solution.
i am attaching here the PCB image with the zener diodes. out of 4 zener diodes one is fine during the testing with diode test mode in DIM. while i tried to check zener voltage with the help of 24 v DC battery and a 2.2K resistor in series with diode, i felt it is above the 24 volt rating. i am surprised with the such high voltage zener diode in this circuit.
please share your valuable suggestion i this regards.

 

[betwixt]

Re: Need Circuit Diagram for "Whirlpool L1961 Quartz pp6" washing machine PCB.

Looking at the condition of that PCB I would say the diodes are the least of your problems.

Thoroughly clean the board then send another photograph of the top and bottom of the PCB. A schematic is probably impossible except from the manufacturer but we might be able to guess what the parts are based on their interconnection with other components.

Brian.

 

[cyberrat]

Re: Need Circuit Diagram for "Whirlpool L1961 Quartz pp6" washing machine PCB.

Are you sure they are zeners? they could just be cheap signal diodes.

Whirlpool boards generally seem to have 1n4000 series diodes in.