I’m going to make a constant current circuit that can be used for many
purpose with very wide current range. The max currents are 0.2, 2 or
20mA, you can choose by a switch.
I don’t know the English name of machines those are just constant
current circuit, so would you let me know those names?
Several weeks ago I wrote that I had finished to design the final
diagram and maybe been able to release it soon. But I had no chance to
buy some parts to make and test it, and I don’t know when I can even
now. So I’ll release the diagram only for get advices or opinions from
those are familiar to electronic circuits. THIS DIAGRAM IS NOT A FINAL
ONE, AND WITHOUT CAUTIONS. NEVER MAKE A CIRCUIT WITH THIS DIAGRAM.
This circuit is designed to be comparably simple, cheap and precise.
Would someone watch and let me know any advices? The diagram can be
seen on web page www.geocities.com/t_tomoedajp/mypage.html. The battery
is about 18V or more.
There are three sections enclosed by boxes. Those are “battery alarm”,
“Max current set” and “ammeter” sections. I decided to use a cheap
voltmeter instead of an ammeter because the cheap ammeter is not
precise and the precise one costs high. The OP amp (This may be a
Japanese name, the triangle amplifier in the diagram) is LMC660. I
don’t adopt FET instead of transister because FET is too difficult for
Now I’m also having advices by professionals and veterans to improve,
so the diagram may be changed without notice.
Thank you, Takashi Tomoeda @Takashi_Tomoeda1