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Old 08-12-2011, 03:38 AM   #16
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Join Date: Nov 2010
Location: Italy, La Spezia

Originally Posted by dbennettya View Post
In both my setups I take the power for the Steve from V+ on the big red wire on the ESC and ground from the normal output to the RX. Power to the ESC comes from the main board connections. Signal to the Steve comes from Jon's connect point.

The symptoms are that when power is applied the ESC initializes and gives the proper tones. Then when you give throttle nothing happens because the signal to the ESC is clamped and isn't a proper signal for the ESC to work.

I soldered a 2.2 Ohm resistor to the ESC power connection V+ and then connected the Steve red wire to the other side of the 2.2 Ohm resistor and the circuit works great with no more latchup.

While troubleshooting this issue I used my O'scope to look at the signals and you can clearly see that without the resistor the Steve output gets clamped to ~ 1.5V and has about 1V amplitude when powered from a battery. This doesn't happen if I use the series resistor or if I use a 5A bench power supply with the resistor. I noticed that the clamping of the signal occurs right after the ESC initializes but before that was the proper signal of about 0 to 4Vpp on the PPM output.

Trust me I know what I'm doing and this is a possible issue that may affect some setups and not others. It is most likely SCR latchup in one of the ICs due to fast rise times of the voltage or a race condition.

Don, very interesting write up

I have long suspected some sort of interference to communication between esc and converter.
Three days ago I disassembled the HP08s /9T / XP12A combos to replace it again with the HP05s / 8T / XP-7A.
I connected the power cables of the converter with those of the ESC.
In a vain attempt to limit the interference I put two sheets of aluminum between the double-sided tape

As a result, the esc is initialized, but the motor would not start.

Then I moved the red and blue wires of the converter at the points shown in the picture.

The motor has been worked and I've had no more problems.
Once I worked with O'scope. These days I really miss it.

Gaui 200 Beastx - An unknown number of bl converted Blade mCP X.
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