what pot for phase inverter balance trim?

[pula58]

I am trying to find a 10K lin (or 20K lin) pot for trimming the phas einverter balance. I have a bunch of Bourns that I have used, but, they are the square type with three leads coming out of the flat bottom. Makes it kind of hard to solder them to an eyelet board since the housing blocks the pins.

So, I have seen some folks here (on TAG) using a type of trim pot with a different body, the legs come out of the side, instead of the flat part of the body. makes them look a lot easier to solder-in.
Have searched mouser, not found the exact right thing yet.

Any tips?

Thanks

P.

[martin manning]

The larger round trimmers are Piher 15mm, which Mouser stocks. I like the Bourns square trimmers, which are half-watt cermet. You can easily bend the leads out to the side and then down to solder them into eyelets.

[Kagliostro]

Pula58, have you a reference schematic for the use of a balance pot in the PI ?

I know someone use trimmers instead of plate resistors to balance LTPI

in which way do you intend to connect your 10k pot ?

Thanks

K

[ToneMerc]

So, I have seen some folks here (on TAG) using a type of trim pot with a different body, the legs come out of the side, instead of the flat part of the body. makes them look a lot easier to solder-in.
Have searched mouser, not found the exact right thing yet.

Any tips?

Thanks

P.

I believe you are talking about the CTS 201 series trimmer.


http://www.mouser.com/ProductDetail/CTS ... rHwb7U8%3d

TM

[pula58]

Ah..thanks tonemerc,. I didn't know CTS made those. That's what I've been looking for.
Looks like the Pihers would be good too(thanks Martin M).

K: The pot ends connect to the high side of the plate loads of the phase inverter. The wiper connects to the power supply.

[Kagliostro]

The pot ends connect to the high side of the plate loads of the phase inverter. The wiper connects to the power supply.

I don't understand but I don't know the PI you have may be depends on that

Which kind of PI are you using, a Concertina or a LTPI ?

K

[pula58]

The pot ends connect to the high side of the plate loads of the phase inverter. The wiper connects to the power supply.

I don't understand but I don't know the PI you have may be depends on that

Which kind of PI are you using, a Concertina or a LTPI ?

K

LTPI

The pot wiper connects to positive voltage supply.
The two other pot connections connect to where the plates R's of the PI normally would connect to the power supply.

[Kagliostro]

OK

so no plate resistors and two pot (or trimmer) ?

K

p.s.: No, 1 pot !

[pula58]

OK

so no plate resistors and two pot (or trimmer) ?

K

p.s.: No, 1 pot !

Imagine a LTP PI. The plates resistors (there are two of them) would normally connect to the + supply.
But, in this case, we place the pot between the supply connections of the plate load R's of the PI. The pot has a small value compared to the plate load R's and is used to tweak the balance.

[Tonegeek]

OK

so no plate resistors and two pot (or trimmer) ?

K

p.s.: No, 1 pot !

This is a Dumble thing. Check out the schematics in the Dumble forum and it will make sense.

[Kagliostro]

Many thanks Pula58 & Tonegeek

I'll go to search a Dumble schematic as to be sure I've understand

Thanks again

K

EDIT: I've seen the Dumble schematic, OK I've understand correctly your last explanation, THANKS