HP 970A Probe Multimeter 3½ digit 1000 count test teardown
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- Опубликовано: 7 сен 2024
- SUPER cool pocket pen probe style multimeter from Hewlett packard
released 1973 mad using custom chips and die bonding, cost 275$ in 1973
links CQ 1973, Radio Electronics 1974
www.decodesyste...
HP Memory project scroll down
www.hpmemorypr...
It uses only 25mA at 9-10V too low at 8V
Charger is called HP 97020B mains powered using capacitors and resistors,
no transformator or isolation !
This is my Hewlett Packard instrument video number 64
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#teardown
#hewlettpackard
#vintage
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I use auto generated subs, i am sorry there are a few spelling errors,
maybe one day they can do it better..
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uses LEDs developed for the HP35 calculator
And sinclair digital watch
From the golden era of HP engineering.
Size 1/3 AA NiMH cells with solder tabs are still available, I replaced them in my 970A and it’s working great. Four cells in two stacks fits the battery pack perfectly. Soldering the tabs together made connections more secure and easier to reassemble the pack. Love the videos, thanks!
A remarkable masterpiece of engineering from the 1970s. I repaired these when I was at HP back in the 1980s. The plastic parts were already degraded and cracking, even way back then. Your 970A actually looks to be in excellent condition for its age.
yes it is cracked all over, tiny almost invisible cracks, something is not perfect with this plastic formular, i was sad to brake the case holder flap, but happy to get it running again, super cool unit, those bubble displays are just fantastic
Now that is a cute piece of kit, spared no expense ;)
The boss of the tool maker who did the backbone plastic part opined (after the part was done) "I'd guess you could get a job almost anywhere!" The shape is a super eclipse.
I first thought it was a hair trimmer.
Nice unit.
I have a 9V standard size battery wich have a DC-DC converter build in toogether with a Li-Ion cell and USB socket for charging. It could deliver what you need. I bought it years ago on Ebay and it still works fine to this day. Maybe they still sell them. The DC-DC converter must be tiny. It though does have some noise on the 9V terminals I can f.ex. not use it in an AM radio but it works fine in my instruments. Over time the converter does drain the battery when not in use.
Love your videos! Keep up the good work!
thanks and i love all your nice comments, i read them all
Hi Thomas, nice Teardown, I love the Old Bubble LED Displays. You could use a small 1300mAh LiPo (Instead of the 14500 LiIon) + the Boost you mentioned. At Pollin(point)de there is an offer for 5pcs Lipo 1300mAh.
Btw, Looks like a electric Hair trimmer🙂
Cheers,
Konstantin
yes charging vise i like the one cell solution the most, but I dont like a little switcher to make noise there, but it is only 3½ digit, so most likely not affected much from a little bit ripple on the supply, but again, it was specially designed to run only on battery power = super clean, so why filter any local suplies
I put an A-23 with a si diode in series in mine, I worked on the design and production engineering for this product. The nicads were horrible. The noise rejection on DC volts isn't good-- direct input to an integrator. Try measuring the battery voltage of a car with it!
May be use 9v rechargeable battery 6f22 design.
Why not just go with the intended Nickel Cadmium - they are still legal for certain tool batteries in the EU, so even amazon still has a few sizes of tabbed NiCD cells...
maybe a small boost convertor?