Good morning fellow nuts, after a short planning and long wait times to get LTZ from china[1], PCB from the Ruhr valley[2] and resistors from the UK[3], I was no longer able to wait and slap everything together. It is a clone of the Williams design in Linear Technology AN86 with 2x25K in parallel as R4, as suggested by Dr. Frank Stellmach from this maillist. The interesting resistors are General Resistance Econistors, the zener plus is buffered with a further LT1013 before breakout with 4mm copper-tellur receptacles[4]. The LTZ1000A has a hat made from a little plastic cap and a o-ring to fix it to the LTZ case. The positive and negative out and also a hole for a guard are on a slotted part of the PCB and around the LTZ I spent some holes to give it a bit of stress-relief.
It worked instantly, I didn't even try step-by-step startup, current limiting was the only safety measure. No stability measurements yet, but the HP34401A at work (where I soldered it during lunch break) and the HP3456A at home have shown the same voltage (the 3456A is calibrated against my work DMM). After finishing the circuit board, I have put it into a tinned sheet iron case[5] and made a makeshift thermoinsulation from bubble wrap and a cardboard box. Result: http://primeintrag.org/LTZ1000A.JPG that is the newborn and one of the spare PCBs. Planned next steps, any hints? 0. Keep it on the HP3456A today and watch infrequently and hope that only the last digit might change 1. Put it in the thermal chamber at work (hot-cold-hot cycle, tmax=80°C) 2. keep it powered for a few weeks 3. Hook it to my 3456A and use EZGPIB to get some voltage-over-time measurements for a few days, although I think that the drift+noise from the HP reference and my LTZ are quite close 4. Beg a cal lab to do a un-accredited HP3458 measurement with results written on a napkin to get a number! (Repeat after a year or so) Regards Hendrik [1] ebay seller polida 2088 [2] http://www.fischer-leiterplatten.de [3] http://www.rhopointgermany.com/ [4] http://www.multi-contact.de/ _______________________________________________ volt-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
