Testing a H744 Regulator on The Bench

Jonathan Chapman lists at glitchwrks.com
Thu Dec 30 15:32:30 CST 2021

Sounds like you're testing things basically the way I was:


I used a large Stancor 24 VAC transformer to supply power to the modules, since they usually see 20-30 VAC from the big transformer in the chassis.

For dummy loads, I like automotive tail lamp bulbs. Series/parallel as necessary to get the load you want. Do keep in mind they get hot enough at rated voltage to melt soft plastics.

> I replaced them with a LED and a resistor.

Many of the later modules do that anyway! I used incandescent lamps because I had them on hand. Wouldn't you know, after reassembling and a few hours of bench running in the PDP-11/10, one of the old ones I hadn't replaced burned out too :P


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