OK I found myself spending much time solving a small problem, when the use of a microcontroller at first seem "overkill". But flexibility to change stuff, and the low cost ao a controller, I find myself more and more seldom using "ordinary" components such as latches etc. A PIC conuld direkt- drive your FET I suppose Best Regards Sven -----Ursprungligt meddelande----- FrŚn: Jack Shidemantle Till: PICLIST@MITVMA.MIT.EDU Datum: den 9 april 1999 21:54 €mne: Re: SV: [OT] Interlocked Pushbuttons >Cost in US is about $1.00 > >> Date: Fri, 9 Apr 1999 20:30:37 +0200 >> Reply-to: pic microcontroller discussion list >> From: MILTON MEDICINTEKNIK KB >> Subject: SV: [OT] Interlocked Pushbuttons >> To: PICLIST@MITVMA.MIT.EDU > >> I don't know what the cost is for the 12C508 is in teh US, but I suggest you use it >> >> >> Best Regards >> >> >> Sven >> -----Ursprungligt meddelande----- >> FrŚn: Michael Rigby-Jones >> Till: PICLIST@MITVMA.MIT.EDU >> Datum: den 9 april 1999 10:59 >> €mne: [OT] Interlocked Pushbuttons >> >> >> >Sorry for yet another [OT]... >> > >> >Ok, I have 3 DPCO momentary push button switches. I want a circuit that >> >will simulate an old mechanically interlocked switch assembly i.e pushing >> >one button will 'release' the other buttons. A PIC is major overkill for >> >this and cost is a strong factor. >> > >> >The output of the circuit is to drive a FET gate. All poles of the switches >> >can be used. >> > >> >One solution I have though of is to use a latch such as a 74HC573 and have a >> >switch tied to each input. A diode OR arrangement from each switch, >> >possibly with a monostable, would strobe the latch. This gives quite an >> >accurate simulation as it would be possible to get two button to lock down >> >simultaneously which is acceptable in this case. The other advantage of >> >this is that I have the possibility to have up to 8 switches with one IC >> >package. >> > >> >Any obviously better solutions spring to mind? >> > >> >Regards >> > >> >Mike Rigby-Jones >> > >> >Jack Shidemantle >Automation & Development Engineer >YSI, Inc. >Yellow Springs, Ohio >