Radio control Tx details

[Coyoteboy]

Anyone know whether the pots in the Tx are used in "variable voltage
out" form or "variable resistance" form to control the channels? I
presume, due to 3 wire connection that its the former but id be pleased

if someone could confirm? Im looking at hacking one and applying
varying voltages to the pot outputs from a uProcessor/DAC.

Ta
J

 

[Jasen Betts]

On 2006-04-06, Coyoteboy <coyoteboyuk@hotmail.com> wrote:

Anyone know whether the pots in the Tx are used in "variable voltage
out" form or "variable resistance" form to control the channels? I
presume, due to 3 wire connection that its the former but id be pleased

possibly... could be neither.

if someone could confirm? Im looking at hacking one and applying
varying voltages to the pot outputs from a uProcessor/DAC.

measure the the input to the tranmitter and get the micro to copy that signal.

Bye.
Jasen

 

[Coyoteboy]

Jasen Betts wrote:

possibly... could be neither.

What else could it be?

measure the the input to the tranmitter and get the micro to copy that signal.

Well thats the plan but i was just hoping someone would have already
worked on them and know but theres little evidence on google so I'll
have to crack out the scope.

Ta
J

 

[John Fields]

On Sat, 08 Apr 2006 08:08:33 -0000, Jasen Betts <jasen@free.net.nz>
wrote:

On 2006-04-07, Coyoteboy <coyoteboyuk@hotmail.com> wrote:

Jasen Betts wrote:
possibly... could be neither.

What else could it be?

could be something like this +v
|
|
.--/\/\/\-----|--+-->|-----------.
| | | |
| .---------+ `--|<---/\/\/\--'
| | | ^
| | . . . .|. . . . |
| | . VCC(8) . |
| | . . |
| `---RES(4) OUT(3)------+-----> out
| . 555 .
+-------TH(6) DIS(7)--
| . .
+-------TR(2) CV(5)--
| . .
===== . GND(1) .
| . . . .|. . . .
| |
`-------------+
|
gnd

---
That's not neither, it's using a variable resistance to control the
output, which is one of the options the OP suggested.

--
John Fields
Professional Circuit Designer

 

[Jasen Betts]

On 2006-04-07, Coyoteboy <coyoteboyuk@hotmail.com> wrote:

Jasen Betts wrote:
possibly... could be neither.

What else could it be?

could be something like this +v
|
|
.--/\/\/\-----|--+-->|-----------.
| | | |
| .---------+ `--|<---/\/\/\--'
| | | ^
| | . . . .|. . . . |
| | . VCC(8) . |
| | . . |
| `---RES(4) OUT(3)------+-----> out
| . 555 .
+-------TH(6) DIS(7)--
| . .
+-------TR(2) CV(5)--
| . .
===== . GND(1) .
| . . . .|. . . .
| |
`-------------+
|
gnd

measure the the input to the tranmitter and get the micro to copy that signal.

Well thats the plan but i was just hoping someone would have already
worked on them and know but theres little evidence on google so I'll
have to crack out the scope.

15 years ago they were using frequency and duty cycle modulation of a the
input signal, this was used to amplitude modulate the carrier

these days AIUI many setups use digital encoding signalling.

Bye.
Jasen