I'm new to circuit building but have always been good at figuring out electronics. I'm hoping to get pointed in the right direction.
I have a bunch of police scanners that operate on 4 AA batteries (4.8V or 6V). I'm sick of replacing the batteries every day (use them for my job). I want to hook up a huge 12V car or lead acid battery to power them. I used my multimeter and measured 1.4ma with the light and speaker off, and up to 2.9ma with the light and speaker on full volume.
What would I need to build a voltage regulator to go from a 12V battery to 6V with a maximum of 3ma? Will the 7805 voltage regulator work or is there something better?
I think my biggest confusion is that I don't understand how to shop for a voltage regulator based on the 3ma. Do voltage regulators work in a "up to X milliamps" mindset? For example, if a voltage regulator states "up to 1 amp", will this work if I only draw 3ma or do I need one specific to 3ma?
I would prefer to keep the circuit as simple as possible in the beginning. I can improve it in time. I'd like to keep the heat down as there will be as many as 4 of these under my car seat. If I need to add capacitors/resistors to reduce noise (either literally audible noise or radio frequencies), then please let me know. I can't stand listening to electrical humming and don't want any interference being generated near my police scanners.
This is what I'm thinking, but I need 6 volts (I think? Or will 5 volts work fine? 4 AA batteries equivilent): http://www.youtube.com/watch?v=WTylbNtZW3A
I have a bunch of police scanners that operate on 4 AA batteries (4.8V or 6V). I'm sick of replacing the batteries every day (use them for my job). I want to hook up a huge 12V car or lead acid battery to power them. I used my multimeter and measured 1.4ma with the light and speaker off, and up to 2.9ma with the light and speaker on full volume.
What would I need to build a voltage regulator to go from a 12V battery to 6V with a maximum of 3ma? Will the 7805 voltage regulator work or is there something better?
I think my biggest confusion is that I don't understand how to shop for a voltage regulator based on the 3ma. Do voltage regulators work in a "up to X milliamps" mindset? For example, if a voltage regulator states "up to 1 amp", will this work if I only draw 3ma or do I need one specific to 3ma?
I would prefer to keep the circuit as simple as possible in the beginning. I can improve it in time. I'd like to keep the heat down as there will be as many as 4 of these under my car seat. If I need to add capacitors/resistors to reduce noise (either literally audible noise or radio frequencies), then please let me know. I can't stand listening to electrical humming and don't want any interference being generated near my police scanners.
This is what I'm thinking, but I need 6 volts (I think? Or will 5 volts work fine? 4 AA batteries equivilent): http://www.youtube.com/watch?v=WTylbNtZW3A
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