Sunny Buddy NTC use

Sunny Buddy NTC use#193960

By Joe Sz - Sun Mar 19, 2017 9:54 am

- Sun Mar 19, 2017 9:54 am #193960

Is there a way to use a NTC Thermistor with the Sunny Buddy?

The schematic shows a NTC net label next to pin 8 but I don't see any other NTC points on the schematic.

Re: Sunny Buddy NTC use#193970

By jremington - Sun Mar 19, 2017 9:02 pm

- Sun Mar 19, 2017 9:02 pm #193970

The LT3652 data sheet explains the proper selection and use of the NTC. Study it carefully.

Re: Sunny Buddy NTC use#193975

By Joe Sz - Mon Mar 20, 2017 5:55 am

- Mon Mar 20, 2017 5:55 am #193975

I have the LT3652 datasheet. I guess I didn't ask the question correctly...sorry.
What I want to know is how to make the connection on the Sunny Buddy. I don't see any connection points on the Sunny Buddy circuit board.

Re: Sunny Buddy NTC use#193983

By jremington - Mon Mar 20, 2017 10:29 am

- Mon Mar 20, 2017 10:29 am #193983

It looks like the PCB has no pad or via connected to pin 8 of the IC, so you will have to carefully solder a wire to pin 8 for connection to the thermistor. The other end of the thermistor goes to GND.

It was a bad idea to leave out that pad, but who knows where to get the right thermistor?

Re: Sunny Buddy NTC use#193985

By Joe Sz - Mon Mar 20, 2017 11:08 am

- Mon Mar 20, 2017 11:08 am #193985

I didn't see any place to make the connection either but I thought I check first.

Mouser has NTC Thermistors with the required values for the LT3652:

B: 3380
R: 10 kOhms 1%

Some are surface mount (0201, 0402, 0603) others are through hole.

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