Power supply question

I have been flying now for a couple of months and doing really great. Anyway, lately I added a Power Module from 3DR to my setup to monitor the battery and whatnot levels. I have removed JP 1 like the wiki says that I need to do. I have been flying with no problems (other than I am experiencing the voltage dance on the hardware vcc in the logs). Prior to using the PM I was using JP 1 and had my esc's connected to the board (logs were not doing the dance).

My question is, do I have to remove JP 1? Can I run both the PM and esc voltage (JP 1) at the same time or will this give to much voltage/ amperage to the board? I ask this because the wiki isn't real clear on this and I also would like to add a servo to the mix here before too long to control my FPV camera that I will also be adding soon.

Thanks!

Setup:

Frame: Hex

Motors: 1000Kv

Props: 10x4.7 carbon fiber

external GPS ant.

3RD (compatible) telemetry radio

software: 2.9.1b

You are correct, the Wiki says "Don't" without tell you why.

If you are familiar with schematics, have you looked at THIS?

Below is an even more simplified version noted regarding your question.

The question is related to connecting two (or more) batteries in parallel in a boat or car. One battery will be slightly higher in voltage (potential) than the other. In the cases where this is practiced, some form of resistance is usually introduced into the circuit to compensate for the imbalances (different levels of voltage) that are in the batteries, or supplies in this case.

HERE is a good article that discusses the battery situation.

HERE is a great explanation by Cliff_J regarding imbalance of parallel sources.

For small current situations this is usually not an issue. High current situations are where the issue of imbalance appears. This is the usual reason for a parallel battery arrangement, higher current demand that a single battery/source cannot supply.

News Flash - You May Already Be Running Parallel Sources!

Now, to be completely open, 3DR has been getting away with a parallel source situation regarding their PDB and ESC connections. The ESC they sell tolerates parallel connections. If you are using their PDB, and a PM, you have 7 supplies paralleled together! 6 summed at the PDB, and then the 7th from the PM if JP1 is installed.

A failure at any source will take the entire supply network down.

In short, there is no need to add JP1 if you are using a PM. Leaving this out allows a separate supply to be used for servos, etc on the PWM Output connections. This allows voltage isolation between the APM electronics and the power hungry servos, etc on the Output side. The common GND (return, 0 VDC) supplies a reference for the entire electronic assembly.

In short, if it ain't broke, don't fix it. Leave JP1 out with a PM.

The PM is made to supply at specification voltage to the APM.

I have been wanting to make a simpler version of my schematic.

Thank you for the motivation and I hope it answers your question or at least supplies you with more knowledge.

Fly On!

-=Doug

Replies

R. D. Starwalt June 5, 2013 at 5:34am

You are correct, the Wiki says "Don't" without tell you why.

If you are familiar with schematics, have you looked at THIS?

Below is an even more simplified version noted regarding your question.

The question is related to connecting two (or more) batteries in parallel in a boat or car. One battery will be slightly higher in voltage (potential) than the other. In the cases where this is practiced, some form of resistance is usually introduced into the circuit to compensate for the imbalances (different levels of voltage) that are in the batteries, or supplies in this case.

HERE is a good article that discusses the battery situation.

HERE is a great explanation by Cliff_J regarding imbalance of parallel sources.

For small current situations this is usually not an issue. High current situations are where the issue of imbalance appears. This is the usual reason for a parallel battery arrangement, higher current demand that a single battery/source cannot supply.

News Flash - You May Already Be Running Parallel Sources!

Now, to be completely open, 3DR has been getting away with a parallel source situation regarding their PDB and ESC connections. The ESC they sell tolerates parallel connections. If you are using their PDB, and a PM, you have 7 supplies paralleled together! 6 summed at the PDB, and then the 7th from the PM if JP1 is installed.

A failure at any source will take the entire supply network down.

In short, there is no need to add JP1 if you are using a PM. Leaving this out allows a separate supply to be used for servos, etc on the PWM Output connections. This allows voltage isolation between the APM electronics and the power hungry servos, etc on the Output side. The common GND (return, 0 VDC) supplies a reference for the entire electronic assembly.

In short, if it ain't broke, don't fix it. Leave JP1 out with a PM.

The PM is made to supply at specification voltage to the APM.

I have been wanting to make a simpler version of my schematic.

Thank you for the motivation and I hope it answers your question or at least supplies you with more knowledge.

Fly On!

-=Doug
Tom June 5, 2013 at 3:58am

Bump
Tom May 31, 2013 at 7:39pm

Nothing? I know that someone out there has something to say on this

This reply was deleted.

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Power supply question

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