Glass Encapsulated Zener Diode

[Dexter'sLab]

Hello Guys,

Anybody here can please help me to identify this zener diode? It would be very helpful if anybody can provide the datasheet for this zener. I would like to buy this zener diode but unfortunately i cant found the datasheet. Thank you very much!

 

[mrinalmani]

Is it so appealing that it tempts you to buy it without being aware of even the gender!

 

[Dexter'sLab]

Is it so appealing that it tempts you to buy it without being aware of even the gender!

Hello Mrinalmani,

Actually I cant proceed buying it because i cant found the datasheet for this component so i cant identify the correct specification for this component. So if you could help me identify this component, it would be great! then i can proceed on sourcing for this component or try an alternative components. thanks for your message anyways..

 

[FvM]

If you know it's a zener diode, measuring the zener voltage gives you most of the missing information.

 

[Dexter'sLab]

If you know it's a zener diode, measuring the zener voltage gives you most of the missing information.

Hello FvM,

Thanks for your msg. I assume its zener base on this website http://www.readconsulting.com/publications/whitepapers/zenerdiodes.html
Actually I cannot Power up the Unit and test the zener voltage.
1. Zener was shorted already.
2. Main unit unable to power up because it needs the interlock from the plc. So we need to install inside the machine before we can test for power up.

Is theres any other way to determine the specs of this zener by the body marking only or maybe anyone can recognize the brand of this zener (the pyramid like logo).
Thanks for your time.

 

[FvM]

It looks like the old Siemens Matsushita logo (now EPCOS). Unfortunately the didn't make z-diodes.

http://www.trademarkia.com/s--m-components-74141059.html

 

[Dexter'sLab]

Thanks FvM. Maybe I can start with this reference to search for the datasheet for this z-diode. I just need the datasheet so I can find alternative for this component if ever it is totally obsolete in the market.

 

[FvM]

MA1020 might be the original diode type.

http://www.semicon.panasonic.co.jp/ds4/SKE00001AED_discon.pdf

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As a first step, I would try to find the expectable zener diode voltage range by analyzing the circuit.

 

[betwixt]

I think speculating it is even a Zener diode is dangerous. It is a diode of some kind but it could be almost anything.

If you measure it's resistance both ways around what reading do you get?

Brian.

 

[SunnySkyguy]

99% probability is a low voltage zener as 1n4148 is most popular silicon diode in glass of that size.

if it is the Panasonic MAZ1020, then it is a 2.0V zener spec'd@5mA but rated for 500mA.

Most likely operating at <10mA.

Temporary fix. - use two Red or Yellow 5mm LED back to back to regulate Vf= 2.0V and provide reverse protection.

Check- remove zener and measure voltage on DMM using diode test. Same for LEDs

 

[Dexter'sLab]

MA1020 might be the original diode type.

http://www.semicon.panasonic.co.jp/ds4/SKE00001AED_discon.pdf

- - - Updated - - -

As a first step, I would try to find the expectable zener diode voltage range by analyzing the circuit.

I already contacted Epcos if possible for them to provide the datasheet or replacement for this component. Im still waiting for the response.

- - - Updated - - -

I think speculating it is even a Zener diode is dangerous. It is a diode of some kind but it could be almost anything.

If you measure it's resistance both ways around what reading do you get?

Brian.

Hello Brian,

I don't think measuring the component itself is reliable.
Diode Test: 0.091 Vdc
Resistance Check: 109 Ohms

- - - Updated - - -

99% probability is a low voltage zener as 1n4148 is most popular silicon diode in glass of that size.

if it is the Panasonic MAZ1020, then it is a 2.0V zener spec'd@5mA but rated for 500mA.

Most likely operating at <10mA.

Temporary fix. - use two Red or Yellow 5mm LED back to back to regulate Vf= 2.0V and provide reverse protection.

Check- remove zener and measure voltage on DMM using diode test. Same for LEDs

Hello Sunny,

Actually I can't power up the PSU unit because it is somehow needed the PLC for interlock. But while troubleshooting offline. I found this component (zener diode) was shorted. I already isolate and remove it from pcb but still short 0.091Vdc (by diodecheck).

 

[SunnySkyguy]

<Dexter
OK Diodes often fail in SC mode from over stress.
If 5mm LEDS are avail. Try those. If too bright, use more in // or get a bigger LED...short Lead time compared to the diode replacement ... for debug purposes. Epcos is not in the diode biz but Panasonic branch may have. Looks like a 12 wk leadtime part.

 

[FvM]

I don't think measuring the component itself is reliable.
Diode Test: 0.091 Vdc
Resistance Check: 109 Ohms

Do you notice any polarity sensitivity? Temperature coefficient? Can you be sure that the component is a zener diode? Could it be a PTC?

 

[Dexter'sLab]

Do you notice any polarity sensitivity? Temperature coefficient? Can you be sure that the component is a zener diode? Could it be a PTC?

I assume its a zener. My reference is http://www.readconsulting.com/publications/whitepapers/zenerdiodes.html
It has the same construction as my component here.

 

[betwixt]

Not a safe assumption I'm afraid. It is one of the most commonly used glass constructions for glass diodes of all kinds and as FvM mentioned, some temperature sensors too.

A DVM 'diode' test simply shows the voltage drop across the junction at a particular current, that current isn't even standardized across different DVM models. I assume your test is with the device out of circuit, do you get a different reading if the device is reversed?

Almost certainly it is a diode of some kind but other than the part number there is little to distinguish them if faulty.

Is it possible to post a photograph of the board it was removed from? It might give clues to it's function.

Brian.