PC Engine CoreGrafx PAD-105 / PAD-106 Power Supply Question. Regulated?

[zborgerd]

The original PC Engine units used the PAD-105 or PAD-106 9VDC 1A Negative tip power supply.  Mainly, I'm curious as to whether or not these were regulated supplies, which were relatively uncommon when these devices were manufactured.

I have a 9VDC power supply that is unregulated, and appears to have a voltage around 11.5-12VDC under load from a CoreGafx.  I'm assuming that this is fine, since most devices have voltage regulators.  However, if anyone would be so kind, could you take a measurement of the official PAD-105 and PAD-106 voltage when the console is running?  It can be measured by slightly pulling out the 2.1 mm plug and measuring its difference against a GND on the chassis (The outside of the video plug seems to be fine).

Thanks!

[grahf]

I'd wager that there is little to no chance of these being regulated. Due to the age of these adapters, you're likely to see a pretty wide voltage range even among the same model supplies.

It doesn't really matter a whole lot though, since like most older electronics the PCE uses the rock solid LM7805 linear regulator internally. As long as you're feeding it a good 6~7v+, you'll be fine. Any more than that is just extra heat.

I personally use a standard 9v 1.5A switching regulator with my PCE and SFC.

[zborgerd]

I agree that the official supplies are probably little more than a transformer and that there was a voltage regulator in the PCE, but couldn't find any photos.  There would likely have to be, since everything internally is largely +5VDC.

Thanks for confirming that there is a LM7805.