Need help to indentify zener diode c3v0ph

Chilli6565 · 3rd May 2009, 11:42 AM

On the schematic I am using for this zener it clearly states it is 8v2 ( 8.2 volts, naturally )...but on the zener it says c3voph..which to me is 3.0 volts?.

It is an Audio note dac two ( circa 1997 ) ....the schematic I have is for a dac4...but The cct's look mostly identical to me ...

The schematic is floating around here somewhere...I will try and post it soon for all to have a look at.....the zener in question is just after the 7805 reg which supplies the digital board.

Thanks

Chilli6565 · 4th May 2009, 04:23 AM

found it !

Mooly · 4th May 2009, 06:35 AM

It's 8.2v and what a strange circuit ( if you don't mind me saying ).
The 8.2v has 5 base emmiter volt drops added to it, in other words 8.2 -(0.7*5) give or take. Absolutely bizzare.
Negative rail is the same.

Chilli6565 · 4th May 2009, 06:47 AM

Hi Karl....how u been...you helped me with another post a while back..it was a cal dac with a dc offset prob and no bleeder resistor, which u fixed.

Anyway, to the problem at hand...yes looks a bit odd...so does that mean you can confirm c3v0ph is an 8.2 volt zener, as that is what is marked on the zener and it came out of the cct marked 8v2 on the scematic????...if I measure from one side of the zener ( with it back in the dac ! ) to zero volts , should I get 8.2 volts??.

thanks

Chilli6565 · 4th May 2009, 06:49 AM

correction...it is marked c3v0ph on the zener....hence my confusion....

Mooly · 4th May 2009, 06:51 AM

Hi, Im fine thanks,
Just read across each zener on volts with it working and should be 8.2 ish. The tolerance of the zener and the base emmiter volt drops are all imprecise and vary with temperature. Each base emmiter drop subtracts 0.7v from the zener.

Chilli6565 · 4th May 2009, 07:01 AM

ok...from one side of the zener I get +7.6vdc and on the other side I am getting +4.4 vdc.
On the other zener it is the same readings only -, of course .?

Mooly · 4th May 2009, 07:13 AM

One end of each zener is connected to zero volts (ground). Just read across the diode or from ground to each leg. Is the +/- 5 volts correct at the emmiter of the final transistor (s)

Mooly · 4th May 2009, 07:18 AM

Check you have 10 volts coming out of those two reg's 7805 and 7905 as this feeds the zeners etc

Chilli6565 · 4th May 2009, 07:22 AM

ok...9.5vdc out out reg......4.94vdc off the last emitter....and 3.2 vdc across the zener !....

3rd May 2009, 11:42 AM	#1
Chilli6565 diyAudio Member Join Date: Apr 2008 Location: Newcastle, Australia.	Need help to indentify zener diode c3v0ph On the schematic I am using for this zener it clearly states it is 8v2 ( 8.2 volts, naturally )...but on the zener it says c3voph..which to me is 3.0 volts?. It is an Audio note dac two ( circa 1997 ) ....the schematic I have is for a dac4...but The cct's look mostly identical to me ... The schematic is floating around here somewhere...I will try and post it soon for all to have a look at.....the zener in question is just after the 7805 reg which supplies the digital board. Thanks __________________ " I love cats....but I couldn't eat a full one. "

4th May 2009, 06:47 AM	#4
Chilli6565 diyAudio Member Join Date: Apr 2008 Location: Newcastle, Australia.	hhhmmmm Hi Karl....how u been...you helped me with another post a while back..it was a cal dac with a dc offset prob and no bleeder resistor, which u fixed. Anyway, to the problem at hand...yes looks a bit odd...so does that mean you can confirm c3v0ph is an 8.2 volt zener, as that is what is marked on the zener and it came out of the cct marked 8v2 on the scematic????...if I measure from one side of the zener ( with it back in the dac ! ) to zero volts , should I get 8.2 volts??. thanks __________________ " I love cats....but I couldn't eat a full one. "

4th May 2009, 06:49 AM	#5
Chilli6565 diyAudio Member Join Date: Apr 2008 Location: Newcastle, Australia.	ooops correction...it is marked c3v0ph on the zener....hence my confusion.... __________________ " I love cats....but I couldn't eat a full one. "

4th May 2009, 07:01 AM	#7
Chilli6565 diyAudio Member Join Date: Apr 2008 Location: Newcastle, Australia.	get this! ok...from one side of the zener I get +7.6vdc and on the other side I am getting +4.4 vdc. On the other zener it is the same readings only -, of course .? __________________ " I love cats....but I couldn't eat a full one. "

4th May 2009, 07:22 AM	#10
Chilli6565 diyAudio Member Join Date: Apr 2008 Location: Newcastle, Australia.	how's this grab ya! ok...9.5vdc out out reg......4.94vdc off the last emitter....and 3.2 vdc across the zener !.... __________________ " I love cats....but I couldn't eat a full one. "


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4th May 2009, 06:35 AM	#3
Mooly diyAudio Member Join Date: Sep 2007	It's 8.2v and what a strange circuit ( if you don't mind me saying ). The 8.2v has 5 base emmiter volt drops added to it, in other words 8.2 -(0.7*5) give or take. Absolutely bizzare. Negative rail is the same.

4th May 2009, 06:51 AM	#6
Mooly diyAudio Member Join Date: Sep 2007	Hi, Im fine thanks, Just read across each zener on volts with it working and should be 8.2 ish. The tolerance of the zener and the base emmiter volt drops are all imprecise and vary with temperature. Each base emmiter drop subtracts 0.7v from the zener.

4th May 2009, 07:13 AM	#8
Mooly diyAudio Member Join Date: Sep 2007	One end of each zener is connected to zero volts (ground). Just read across the diode or from ground to each leg. Is the +/- 5 volts correct at the emmiter of the final transistor (s)

4th May 2009, 07:18 AM	#9
Mooly diyAudio Member Join Date: Sep 2007	Check you have 10 volts coming out of those two reg's 7805 and 7905 as this feeds the zeners etc

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