zener in HP 6111A D.C. power supply

[Joe L.]

Hi. I'm repairing a H.P. 6111A D.C. power supply and need to replace a
shorted diode. It is CR32. If anyone out there has the service manual,
could you please tell me what this part is? It seems to be marked
GE1-3.2Z so it's not a stretch to think that it's a 3.2V zener, but I'd
like to know for sure. Thanks.

--
Joe

 

[Robert Baer]

Joe L. wrote:

Hi. I'm repairing a H.P. 6111A D.C. power supply and need to replace a
shorted diode. It is CR32. If anyone out there has the service manual,
could you please tell me what this part is? It seems to be marked
GE1-3.2Z so it's not a stretch to think that it's a 3.2V zener, but I'd
like to know for sure. Thanks.

--
Joe
However, as the zener voltage goes down, their abruptness degrades as

well,and a 3.2V zener is not much better than a forward biased diode.

 

[Dave]

Robert Baer wrote:

Joe L. wrote:

Hi. I'm repairing a H.P. 6111A D.C. power supply and need to replace a
shorted diode. It is CR32. If anyone out there has the service manual,
could you please tell me what this part is? It seems to be marked
GE1-3.2Z so it's not a stretch to think that it's a 3.2V zener, but
I'd like to know for sure. Thanks.

--
Joe

However, as the zener voltage goes down, their abruptness degrades as
well,and a 3.2V zener is not much better than a forward biased diode.

Is that because the low-voltage ones use the zener process, whereas the
high voltages ones use an avalanche process? I'm just interested. Sorry
I can't help the OP about that diode.

 

[Jules]

Joe - CR32 is to protect against application of reverse polarity from any
external source. It is spec'd as "200V 500mA" so any fat rectifier type
would do. There is some virtue in using a device with a smallish current
rating, 1N4001 etc, as these should fail 'short' as yours did, providing
permanent protection!

 

[Joe L.]

In article <4321e488$1@news.greennet.net>,
"Jules" <jx.omegxa@memxbers.v21.cxo.uk> wrote:

Joe - CR32 is to protect against application of reverse polarity from any
external source. It is spec'd as "200V 500mA" so any fat rectifier type
would do. There is some virtue in using a device with a smallish current
rating, 1N4001 etc, as these should fail 'short' as yours did, providing
permanent protection!

Jules,

Thanks for the info. I installed a 1N4003 and the power supply is back
to normal. I appreciate the help.

--
Joe