Test Equipment.... The missing link

Call it "HP 4145B"? ;)

Cheers

Phil Hobbs

Do not let Mike or others talk you out of this project. But do read their advice.

Mean while google Neil Heckt and AADE. Selling home brew test equipment can be done.

Dan

Hey Dan, I too have one of his LC meters. Use it for lower range values. His meter was some of my inspiration.

Ciao, harry D.

Neil was my load in about 1968 at the Sat V breadboard in Huntsville. Very smart engineer.

Dan

For Zeners I use a scope. Yup.

My hand can pick up over 50 volts AC, so I put the Zener on the probe, tip to ground and touch the tip. Voila, a waveform of the 60 Hz in the amplitud e of the Zener rating, if it is good. Of course it only works on the lower wattage ones, the bigger ones usually have too much leakage, but those can usually be tested in circuit live anyway. Most higher wattage Zeners are re legated to clamping duty now anyway, with most regulators being active and just using them for a reference. (and then we have Tektronix which used to use one Zener for a half dozen sources or more, what were they made of gold or something ?)

I also used to use a scope for faster testing of lytics. Once you learn how to read it it is the best way hands down, but you have to get used to it. You need to feed a 400 mV, 1 KHz square wave with a source impedance of abo ut 360 ohms and let the DUT shunt it. I have used other test signals but se ttled on this due to experience, it is the most versatile and accurate. And you set the scope to DC, using a positive or negative going square wave an d it will also tell you if the cap is shorted. I designed a small handheld unit with a simple, yet more effective, bar graph LED display that worked o n a similar principle but at the time I was working and had no time for suc h things. The scope method was there and worked, so I used it for decades. The difference is many people don't use the scope all the time, but I did. I literally had a scope before a decent meter. I learned to really use it a nd it helped alot. I was fast. (it was on a scopemobile along with an isola tion transformer and a few other things)

I used to work on 3 benches at once, I would troubleshoot the 3 units and b y the time I got to the last one they still weren't done with the first one . Sometimes I fixed the last one and took another one, sometimes I went out for a smoke break. The owner of the company ran the road at times and woul d pull up in the truck, in the beginning he asked "Do I pay you to smoke ?" . I just said "Yes". Later, I replied "Handsomely". And then they used to p ay me (and a very few others) to date every Friday so in the afternoon they would ask me how late I'm staying, and then write the check and give it to me. So he pulls up and asks the usual question and I said "Yes, in fact yo u already have".

The owners got sick of Ohio and moved to Florida and opened up shop. I coul d have went but I have no connections down there and the whole place smells like a dirty fish tanks. So much for that. I had another job anyway, about a third of the driving. I got sick of getting home an hour after quitting time, with this place usually the heater in the car wouldn't even get warm by the time I made the trip, including stopping for beer. So I only worked for that place again ad hoc, part time.

I had been playing around with a similar idea but stopped when I saw

Regards Werner Dahn

I had been playing around with a similar idea but stopped when I saw

Regards Werner Dahn

Yep, every good lab needs a curve tracer. Have not had one for 20 years.

Ciao, Harry D.