Hastings Vacuum Gauge VT-4B modern part

[Steve]

We have a blown Hastings VT-4B. The part is D3 as listed in
http://www.repairfaq.org/sam/vt46sch.gif
The original part number looks like V1301A1 (13-10-076A). I can't
find any specs on this part. Anyone have a datasheet or specificatins
for this?

All help appreciated.

Steve

 

[N Cook]

We have a blown Hastings VT-4B. The part is D3 as listed in
http://www.repairfaq.org/sam/vt46sch.gif
The original part number looks like V1301A1 (13-10-076A). I can't
find any specs on this part. Anyone have a datasheet or specificatins
for this?

All help appreciated.

Steve

Is that a varistor or non-polarised transient suppressor of 130V rating?

 

[Steve]

Is that a varistor or non-polarised transient suppressor of 130V rating?

No clue. The original is history, the customer plugged the unit into
230V. No way to see any case markings or even physical dimentions of
the original.

Thanks,
Steve

 

[Sam Goldwasser]

No clue. The original is history, the customer plugged the unit into
230V. No way to see any case markings or even physical dimentions of
the original.

I don't know exactly what technology that is, but it's function is a surge
suppressor. The unit will run if that part is removed. Whether anything
else has been damaged, only way to know is to try it. I'd suggest checking
D1, D2, C1, and R3. If they are good (or after replacing whatever isn't!),
try it without D3.

130 V may be a bit close to 125 VAC, maybe 140 or 150 V? Replace with
modern device and add a fuse while you're at it. With the fuse, even
if D3 isn't replaced with anything, a surge or plugging into 230 VAC shouldn't
result in damage beyond D1 in any case.

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[whit3rd]

I don't know exactly what technology that is, but it's function is a surge
suppressor. The unit will run if that part is removed.

Not this time, it isn't a surge suppressor. This unit uses the
varistor
as a pre-regulator of the AC input, and it might be intended to
conduct
even in the absence of a surge.
The part number was probably V130 LA1 (the LA series was from
Panasonic); modern equivalent seems to be ERZ-V27D201.

Radio Shack part #206-568 is close enough
<http://www.radioshack.com/product/index.jsp?productId=2062574&cp>

 

[Sam Goldwasser]

Not this time, it isn't a surge suppressor. This unit uses the
varistor as a pre-regulator of the AC input, and it might be intended to
conduct even in the absence of a surge.

The part number was probably V130 LA1 (the LA series was from
Panasonic); modern equivalent seems to be ERZ-V27D201.

Radio Shack part #206-568 is close enough
<http://www.radioshack.com/product/index.jsp?productId=2062574&cp>

That's interesting. It would indeed, though the unit would still work
without it on 115 VAC, but with slightly worse regulation and R3 would
get a bit toastier than normal.

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
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Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
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[Steve]

Thanks for the input everyone. Mouser sells the V130LA1's by
Littelfuse, should do the trick I hope.


On a different note, the customer also sent in a newer unit, blown up
the same way. It has the same model number, but different board.
Looks like it uses 3 terminal regulators & an op amp for its circuit.
Both filter caps pre-regulators exploded, hopefully not taking out
everything else down circuit with the massive ac ripple that likely
followed. That one comes next though.

Steve

 

[Steve]

What sort of output is to be expected on this type of unit? I'm
getting somewhere around .5VRMS @ 600Hz square wave. I think it's
proper, but I don't know much about these gauges.

Thanks,
Steve

 

[Sam Goldwasser]

What sort of output is to be expected on this type of unit? I'm
getting somewhere around .5VRMS @ 600Hz square wave. I think it's
proper, but I don't know much about these gauges.

I'm not positive but the voltage sounds about right and the frequency
isn't critical. The spec for the VT-4 is 320 mV AC. But that's loaded
with the TC tube.

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
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| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.