OK, from hunting around I know that the remote turn on wire appears at pin 4 (DTR) of the sled serial port. I am looking to power a simple RS232 level converter (and some other minor circuitry) off the remote wire. Can someone tell me how much current/power I can draw from the empegs amp remote line? I'm only looking at say 100-200mW.

If possible I'd like to get away without finding a voltage regulator with an inhibit line and just running a standard regulator off the amp remote line.

In the final system I would have the amp remote wire going to 1 regular amp, the remote line of my cd changer and powering a MAX202 based circuit.

Also can someone confirm or deny whether or not the serial port on the sled is different to the empeg one? I know for sure the port on the empeg is PC type (i.e. DTE). I have seen mention that the sled is opposite (i.e. DCE) but it is setup for connecting to GPSes etc. This doesn't make sense to me since I would expect a GPS to be the DCE device. I have to rip my dash apart to find out, but I need to know before I can lay out the board.

Thanks guys,

The amp remote line needs to power the tuner, ISTR this is around 100-200mA @ 12v. A decent amp will draw no more than ~5mA from the remote line as it will just turn a mosfet switch on.

The amp remote line is rated at 1A. It's fused with a resettable fuse, and the high-side driver that switches it is overcurrent/overtemperature protected too. Just try it and see if it works.

Hugo

Well I'm replying to my own post, but someone else might want to know too.

The sled serial port is definitely a DCE. i.e. it transmits on the RX pin meaning a straight through connection to a PC but a null would be required for connecting to most serial type "peripherals" in the car.