[Milsurplus] PE-104-A Power Unit Vibrator Help

[Bruce Gentry]

The power source is probably constant but varying. Two diodes could 
allow the regulator to draw from whichever side of the transformer is 
not switched to ground at the moment. Another thing is, once the module 
starts to "buzz", the voltage from the diodes would be twice the input. 
The source voltage is on the center tap of the transformer primary, if 
one end is grounded, the other will be raised to twice the input. The 
regulator in the module would be receiving square wave pulses of twice 
the input sitting on a "pedestal" of the input voltage. Considering the 
module is "smart", it  probably  monitors the doubled voltage  and shuts 
off if a fault elsewhere in the power supply is overloading the transformer.

         Bruce Gentry, KA2IVY

On 2/26/18 12:01 AM, Robert Downs wrote:
>
> Interesting. So the switch in the thing is shorting out its own power 
> source 50% of the time.  That makes it the electronic analog of a 
> shunt type vibrator.
>
> Robert Downs - Houston
>
> WA5CAB
>
> *From:*milsurplus-bounces at mailman.qth.net 
> [mailto:milsurplus-bounces at mailman.qth.net] *On Behalf Of *Bruce Gentry
> *Sent:* Sunday, February 25, 2018 19:36 PM
> *To:* Milsurplus at mailman.qth.net >> Milsurplus
> *Subject:* Re: [Milsurplus] PE-104-A Power Unit Vibrator Help
>
> The modules are powered entirely by the power on the primary of the 
> transformer. Therefore, the voltage needed to operate the 
> microprocessor the drives the MOSFETS is regulated down from the 
> battery voltage on the transformer, not the 6 volts that normally 
> operates the vibrator. Apparently, the designer didn't feel it was 
> practical to derive the microprocessor voltage from such a wide range.
>
>      Bruce Gentry, KA2IVY
>
> On 2/25/18 7:20 PM, Robert Downs wrote:
>
>     OK. But it still doesn’t make sense that you have to have one of
>     each in order to operate from all three primary voltages.  The
>     DY-88, like most of the rest of the Korean War (and some of the
>     late WW-II) supplies is designed to use either of two vibrators,
>     one series fed and the other shunt fed. The switch over between
>     the two is handled by the socket wiring.  But both have 6V coils. 
>     A similar situation exists in all of the dual or triple primary
>     supply units dating all of the way back to the PE-104. Resistors
>     are switched in to cater to the two or three primary supplies in
>     use.  The solid state designers should have just used those.
>
>     Robert Downs - Houston
>
>     WA5CAB
>
>     *From:*milsurplus-bounces at mailman.qth.net
>     <mailto:milsurplus-bounces at mailman.qth.net>
>     [mailto:milsurplus-bounces at mailman.qth.net] *On Behalf Of *Bruce
>     Gentry
>     *Sent:* Saturday, February 24, 2018 22:31 PM
>     *To:* Milsurplus
>     *Subject:* Re: [Milsurplus] PE-104-A Power Unit Vibrator Help
>
>     Dislexia strikes!  The low voltage version is for 3-18 volts not
>     3-13, the high voltage version is for 12-38 volts not 13-28.   The
>     low voltage one is fine for 6 or 12 volts, the high voltage  for
>     12 or 24 volts.  If the ability to operate the DY-88 on 6-12-24
>     volts is desired, it would still require  both versions of the board.
>
>         Bruce Gentry, KA2IVY
>

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