After a long search for a suitable curve tracer circuits I've settled on the old one from Heathkit. The circuit is pretty simple, although some parts are obsolete and I'll have to find a replacement for them.
The power transformer is used to power both low voltage and high voltage parts of the circuit. I've marked the voltages on the schematic. For HV part my simulator shows that I need 80V CT in order to get 50V p-p after rectifier, and 300V CT in order to get 240V p-p. In the specs they say that the device can deliver 1A@40V and 200mA@240V, so I beleive that specifying [email protected] and [email protected] should be sufficient. However, I'd appreciate any thoughts on this matter.
As for replacement parts, here's what I'm going to use:
1N2071 -> 1N4007
FT123 -> BD159
TA7520 -> FJL6920TU
This beast has quite a lot of switches, all rotaries are 2-deck which is not convenient and expensive. Luckily, at least 2 of these switches can be substituted with 1-deck and additional resistors (like SW4 and SW7). I'm planning to substitute the SW6 with a copule of 3-pos toggle switches. SW8 looks like it should be able to carry HV and high current, so the only way of resolving this (and still have some $$$ left) is to use a bank of relays operated by a cheap Lorlin switch. The whole asembly should cost ~ 20-25$ which is not that bad.
SW4 seems to carry some HV and high current as well. I was looking at some cheap C&K switches that claim to carry 2.5A@125VAC and 350mA@125VDC which may be sufficient. However, I'm thinking about substituting some positions with relays and using a cheaper Lorlin there to be safe.
As always, if anybody has any thoughts or suggestions, they are very welcome.
I'm going to update this thread when I have any news about the project.
The power transformer is used to power both low voltage and high voltage parts of the circuit. I've marked the voltages on the schematic. For HV part my simulator shows that I need 80V CT in order to get 50V p-p after rectifier, and 300V CT in order to get 240V p-p. In the specs they say that the device can deliver 1A@40V and 200mA@240V, so I beleive that specifying [email protected] and [email protected] should be sufficient. However, I'd appreciate any thoughts on this matter.
As for replacement parts, here's what I'm going to use:
1N2071 -> 1N4007
FT123 -> BD159
TA7520 -> FJL6920TU
This beast has quite a lot of switches, all rotaries are 2-deck which is not convenient and expensive. Luckily, at least 2 of these switches can be substituted with 1-deck and additional resistors (like SW4 and SW7). I'm planning to substitute the SW6 with a copule of 3-pos toggle switches. SW8 looks like it should be able to carry HV and high current, so the only way of resolving this (and still have some $$$ left) is to use a bank of relays operated by a cheap Lorlin switch. The whole asembly should cost ~ 20-25$ which is not that bad.
SW4 seems to carry some HV and high current as well. I was looking at some cheap C&K switches that claim to carry 2.5A@125VAC and 350mA@125VDC which may be sufficient. However, I'm thinking about substituting some positions with relays and using a cheaper Lorlin there to be safe.
As always, if anybody has any thoughts or suggestions, they are very welcome.
I'm going to update this thread when I have any news about the project.
