Hi all,
I'm a novice with electronics so please bear with me. I'd like to build a voltage-controlled relay, specifically a sort of "gate" that will allow current to pass (turn on) above 12.8 V or so and close at voltages below that. I'm looking to use it in my motorbike to connect it with my phone charger so it will only charge when the bike is running and being charged by the alternator (at which point the terminals will read out a voltage above 12.8 V or so).
From perusing the forum and the web, it seems a comparator (an LM311 or so) coupled with zener diodes will do the trick, but I'm dumbfounded when it comes to building it and choosing what resistors and capacitors to use. Can anyone offer advice or point me to a circuit diagram? I've looked at the diagram here. How valid is it? Thanks!
David
P.S. Can a moderator change the title to "Help with Voltage-Controlled Relay"? I'm getting the bug where I can't submit a thread unless the title is 20 characters or less. And I can't PM since I just joined =( Thanks!
I'm a novice with electronics so please bear with me. I'd like to build a voltage-controlled relay, specifically a sort of "gate" that will allow current to pass (turn on) above 12.8 V or so and close at voltages below that. I'm looking to use it in my motorbike to connect it with my phone charger so it will only charge when the bike is running and being charged by the alternator (at which point the terminals will read out a voltage above 12.8 V or so).
From perusing the forum and the web, it seems a comparator (an LM311 or so) coupled with zener diodes will do the trick, but I'm dumbfounded when it comes to building it and choosing what resistors and capacitors to use. Can anyone offer advice or point me to a circuit diagram? I've looked at the diagram here. How valid is it? Thanks!
David
P.S. Can a moderator change the title to "Help with Voltage-Controlled Relay"? I'm getting the bug where I can't submit a thread unless the title is 20 characters or less. And I can't PM since I just joined =( Thanks!