Device to reset power...

Try something like this : +------------------------+--------------o V+ | | (To suit relay) --- +------+ IN4148 ^ |\ | /|\ | \ | Relay coil | | \ | | +------+ | | +-------------------------+ | +-+ 1k |/ SIgnal o-----/\/\/-----+------+---------| 2N3904 | | |\>-+ --- / | Serial 1N4148 ^ \ 10k | Or TTL /|\ / | Port | \ | | | | Gnd o-----------------+------+-------------+----------- 0V 'Signal' is any line you can turn on/off, such as RTS (or even TxD if you can send arbitrarily-long breaks). It can either be an RS232 signal, or a TTL one. Choose the external PSU to suit the relay coil voltage. Connect the contacts of the relay to switch whatever you need to swtich. If possible, switch the low-voltage side of the PSU transformer (if the unit uses a wall-wart PSU, this is easy!). -tony