Cable documentation updated. - VCC, transistors...

[Vitaly]

I've got a tons of similar questions:
1. What to do with VCC pins
2. Which transistors to use.

So, I did some updates in documentation. The address is the same:

[Brad]

Thanks for your alternatives on Transistors, could you advise on the suitability or best choice from the followng which are in my parts box
2N3904 - 2N3906
or BC337-25 - BC327-25
or BC549 BC547 BC557

[Brad]

Hi,
I tried the 'suck it and see' method, and I can confirm that the BC547B and BC557 work fine with the interface.
Thanks for any help received

[Michael Guslick]

Vitaly -

In the PPM signal sent from the transmitter, approximately how long is the pause between the PPM 'packets'?

[Vitaly]

~ 18-20 mS between packet heads

[Ken Hewitt]

In RC PPM the 'Packet' is called a Frame made up of the seperate channel pulkses, this frame is usually 18-20mS.

The 'Pause' is not actual a pause but an extra long extra channel pulse, this is called the sync pulse.

There used to be two methods used by different equipment makers, one used a fixed Frame rate and the sync pulse was the time left in the frame after all the channel pulses were sent. The other method used a fixed lenght of sync pulse so the frame rate varied as the channel pulses varied.

Most manufacturers these days seem to stick to the fixed frame rate system as some servo's don't like varying frames rates.