AlphaOne

I almost have my alarm setup except for a few trip wires (hood, door, hatch...) that feeds a ground signal when tripped. my alarm triggers only work when a +12v signal is sent. so what do i need to do. I preferr not to use a bunch of relays to convert the ground signal to a +12v signal. anyone have experience with this.


btw - if anyone needs help w/ their alarms, let me know, cause outside of this one problem im having I can offer allot of help.

thanks,
AlphaOne

cpt_koolbeenz

what you need is a 7404 Hex inverter...

AlphaOne

thanks, I'll look into that. you sure it'll work?

rcldesign

I don't think a 7404 will work since it is designed to work in a 5V system, not a 12V system. A SPDT relay from radioshack will work. Wire the magnet to the 'sensor' (switched ground) and a 12V source. Then, have the normally closed pin on the relay go to ground, and the normally open pin go to 12V, and the common pin to the alarm. When the 'sensor' gives a ground signal, the relay will flip, and feed +12 V to the alarm; when the 'sensor' gives a 12V signal (not ground), a ground signal will be sent to the alarm.

AlphaOne

there is probably a hex inverter that will support 12v tho. I just need to find one that will carry enough amps thorough the i/o pins. The advantage to a component is that they are much smaller than relays and there are no moving parts. I'll let you guys know if I find one.

later,
AlphaOne

Sam Lin

I'd be interested in what you find also, please do keep us informed. Perhaps try e-mailing and asking Newark, at newark.com - they've got a huge selection of components and what seem to be very qualified tech support.

Sam

rcldesign

as does Digikey (www.digikey.com) and mouser (www.mouser.com)