NJ_GOKEMEIJE@FANDM.BITNET (06/25/91)
In my A500 introduction manual it says that I can use 100 mA of the Parrallel Port 5V line (pin 14). Unfortunately that seems not to be true: It looks like it is 5V over a 100 Ohm resister: if I draw about 20 mA, the voltage drops down to about 3V. (Or am I overabusing my power supply?) Thanks, Nils Gokemeijer (NJ_GOKEMEIJE@FANDM.bitnet)
prak2@pttrnl.nl (06/27/91)
In article <B92671994000426C@FANDM>, NJ_GOKEMEIJE@FANDM.BITNET writes: > In my A500 introduction manual it says that I can use 100 mA of the > Parrallel Port 5V line (pin 14). Unfortunately that seems not to be true: > It looks like it is 5V over a 100 Ohm resister: if I draw about 20 mA, the > voltage drops down to about 3V. > (Or am I overabusing my power supply?) > > Thanks, Nils Gokemeijer (NJ_GOKEMEIJE@FANDM.bitnet) All power-outputs on the parallel/serial ports have this problem. They do have a resistor in their lines. This is done to protect your Amiga from being short-circuited by IBM-cables. This feature is present on the A500 and A2000 (i guess for the A300 too, but i'm not sure). The A1000 does not have this problem because of it's non-IBM connectors for the parallel and serial ports. You can solve this problem (if you want too), by by-passing the resistor. The schematics can be found in your user manual. You will void your warranty if you do this. jan.
manfred@edomdo.UUCP (Manfred Dolag) (06/28/91)
In article <B92671994000426C@FANDM> NJ_GOKEMEIJE@FANDM.BITNET writes: >In my A500 introduction manual it says that I can use 100 mA of the >Parrallel Port 5V line (pin 14). Unfortunately that seems not to be true: >It looks like it is 5V over a 100 Ohm resister: if I draw about 20 mA, the >voltage drops down to about 3V. >(Or am I overabusing my power supply?) > >Thanks, Nils Gokemeijer (NJ_GOKEMEIJE@FANDM.bitnet) -- there is a emi-filter between pin 14 and internal +5volt. the drop may be normal. in a2000 there is an 47 ohm resitor. - - - - Manfred Dolag, Edotronik GmbH (ECG018), Tel. +49 89 404093, FAX +49 89 402293 Path: ...!cbmvax!cbmehq!cbmger!edomdo!manfred