Author Topic: PC ENGINE POWER SUPPLY.......??!!!  (Read 4899 times)

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Offline TonyN

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PC ENGINE POWER SUPPLY.......??!!!
« on: April 26, 2013, 06:07 PM »
Hi, just bought some power adaptors for use with Japanese PC Engines.

As you guys know PCE use DC 9v negative centre pin at about 1.25amp.
After ordering new power supplies those  I received were  'new' old ones for the Atari Jaguar and were DC 9v negative centre pin BUT on the voltmeter they are giving out 13 volts.  What confuses me and consoles me (excuse the pun) is that I recently bought another PCE which had a 9v adaptor which gave out 13v, when I emailed the previous owner he said he had used it on that PCE for years!? 

 So, is a 9v supply which gives 13v on a Meter safe to use with my PCE?

Thanks in anticipation.
« Last Edit: April 27, 2013, 11:51 AM by TonyN »

Offline Chilly Willy

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Re: PC ENGINE POWER SUPPLY.......??!!!
« Reply #1 on: April 26, 2013, 09:09 PM »
The voltage out from an adapter may vary with the load. A VOM probe is designed to not present much of a load compared to the actual device, so you often don't see the "proper" voltage from it.

Voltage regulators in devices take a higher voltage, and make a regulated lower voltage out of it, so generally the supply voltage can vary HIGHER without a problem... the limit for how much higher the supply can be is usually set by the voltage limit of the capacitors in the supply input circuit. If the caps used can take 15V, that's the limit for the supply, even if it says 9V is supposed to be used. It's pretty common for people to use power adapters with the "wrong" voltage on consoles... far more important is the amount of current the adapter can supply, and having the proper polarity connector.

Offline goombakid

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Re: PC ENGINE POWER SUPPLY.......??!!!
« Reply #2 on: April 26, 2013, 10:54 PM »
The regulator inside most consoles is the 7805 Voltage regulator. Their input voltage (voltage from the adapter) can vary from 5V to 18V. The 7805 regulates it to ~5V for output (to various parts of the console).

Didn't know that adapters could output more voltage than marked. However, under regular load, it should be about 9V going into the system, since higher voltage may be needed at other parts of the console.

Offline gtsamour

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Re: PC ENGINE POWER SUPPLY.......??!!!
« Reply #3 on: April 27, 2013, 07:29 AM »
I use new PSUs for my consoles these days unless I have no choice. Instead of getting a step down or step up converter, better buy a whole new PSU maching the specs needed from the console.
I always preffer switch PSUs because they're regulated and provide more Amps for their small size and weight.

Offline TonyN

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Re: PC ENGINE POWER SUPPLY.......??!!!
« Reply #4 on: April 27, 2013, 11:46 AM »
Hi, the power pack seller, who has been around for a long tome and knows his stuff, got back to me and said 'They're rated at 9v on load, but will measure more offload.'
So, all seems well.  :)
« Last Edit: April 27, 2013, 12:09 PM by TonyN »