Hello Forum Members:
I really need your help. I have a radar detector in my vehicle. When the device detects a radar source, a small LED blinks. This visual cue is too small and I am trying to have the detector light a previously-installed LED cluster that operates on a 12VDC source. The line going to the present LED is providing enough voltage and current to power that small LED but not nearly enough to power my preferred LED cluster. The voltage I am measuring to the small LED is somewhere in the order of 5 volts (it is difficult to measure since the LED only blinks intermittently). My first thought was to install a 5volt relay in place of the small LED and then power my cluster with 12v sent through the relay. When I tried that, there wasn't enough power to close the contacts on the relay. The coil in the relay is rated at 5v and 89mA. Apparently the current going to that small LED must be minute. I read from another post that a transistor could be used as a switch to power a relay and I'd like to try that. My only training in electricity is the 8 credits of Physics I took in college about a billion years ago. I can follow a schematic pretty well however. I am just not sure which transistor type to use (e.g. a NPN, PNP, FET, MOSFET, etc), how it should be wired and whether any resistors have to be added to protect the line from my radar detector. The detector cost my $1000 and I want to make absolutely sure that no current finds its way back into the detector body and blows something out. If you can please afford me some straight forward schematics as to how I may solve this dilemma, it would be genuinely appreciated. Please remember that I am not an electrical engineer (obviously) and I need something simple and uncomplicated. Thank you.
I really need your help. I have a radar detector in my vehicle. When the device detects a radar source, a small LED blinks. This visual cue is too small and I am trying to have the detector light a previously-installed LED cluster that operates on a 12VDC source. The line going to the present LED is providing enough voltage and current to power that small LED but not nearly enough to power my preferred LED cluster. The voltage I am measuring to the small LED is somewhere in the order of 5 volts (it is difficult to measure since the LED only blinks intermittently). My first thought was to install a 5volt relay in place of the small LED and then power my cluster with 12v sent through the relay. When I tried that, there wasn't enough power to close the contacts on the relay. The coil in the relay is rated at 5v and 89mA. Apparently the current going to that small LED must be minute. I read from another post that a transistor could be used as a switch to power a relay and I'd like to try that. My only training in electricity is the 8 credits of Physics I took in college about a billion years ago. I can follow a schematic pretty well however. I am just not sure which transistor type to use (e.g. a NPN, PNP, FET, MOSFET, etc), how it should be wired and whether any resistors have to be added to protect the line from my radar detector. The detector cost my $1000 and I want to make absolutely sure that no current finds its way back into the detector body and blows something out. If you can please afford me some straight forward schematics as to how I may solve this dilemma, it would be genuinely appreciated. Please remember that I am not an electrical engineer (obviously) and I need something simple and uncomplicated. Thank you.