Recent content by DiodeDave

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    Current limiting resistor power rating question

    Thanks Bob The flashlight was from Ebay, perhaps there was a translation problem. At the advertised 13000 lumen rate, it is the brightest flashlight I have seen, whatever the actual rating. If you look into the light, you have spots for quite a while! At any rate, I left the LED connected to...
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    Current limiting resistor power rating question

    Thanks The LED has been on for an hour and is still at room temp, or slightly higher. I put my ammeter in series with the leads on the LED to get my 100ma rating. The 12v is what I get with my meter across the leads of the 12v battery from my UPS. The LED is from a flash light with 3 AAA...
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    Current limiting resistor power rating question

    Thanks Bob. It's been working for an hour and everything is ok. For kicks, I put paper towel on it. It's ok too.
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    Current limiting resistor power rating question

    I have LED with a 100ma rating, 4.5v voltage drop and 12v power source. The formulae I have been using call for a resistor of 82 ohms with 1w rating. I have a 100 ohm 1w resistor in series with this LED and it gets too hot to hold. What am I doing wrong?
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    Led Flashlight Help

    The LED draws 180ma on my meter. If I use the LED calculators found on the internet, the result is to use a 1 ohm resistor since the source voltage and forward voltage are the same. I'm thinking Audioguru has the solution. The voltage drops to about 3.4v when the LED is turned on. There...
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    Led Flashlight Help

    The dc/dc converter is rated at 3A What is my solution? Do I dial the dc/dc converter down?
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    Led Flashlight Help

    I have an LED flashlight that runs on 3 AAA batteries. I want to run it with a 12 volt battery. I have adjusted a dc to dc converter to 4.2 volts. The flashlight gets very hot. (It doesn't get hot when the AAAs are connected) I've checked my volt meter to see if the dc to dc converter was...
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    Transient Voltage question

    Adam I'm not sure what you are asking. I will have a 40a automotive relay in series with the batteries. When the relay is closed, and opened, the controller and motors will not be operating. There won't be any load except for possibly a few small LEDs and a brushless fan from a computer CPU...
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    Transient Voltage question

    I have a DC motor controller powered by 2 12v batteries in series. (The controller is a 4qd Pro 150 which powers my locomotive. The leads from the batteries have a 30a fuse.) I would like to put a relay between the batteries and controller in order to turn off all power to the controller. I've...
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    AGU FUSE HELP

    Now you have me wondering. The circuit has regenerative braking. Was I trying to put too much back into the batteries? I traveled down that hill 2 other times with more load (my wife and myself rather than just my arse).
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    AGU FUSE HELP

    I have a 60a agu fuse in my 24v dc train controller. After running for approximately 20 hours my engine stopped. I was going down hill at the time of the malfunction. This was after nearly one mile of up hill travel. The motors and controller heat sink were cool. The fuse looked fine and...
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    Bad Capacitor?

    Huh? Oh well, I scrubbed the board with a tooth brush and picked off anything that didn't look friendly. I also put some heat on any area that looked like it might have had impact or a crack. I heated until I saw the solder melt. Nothing. I'll try a new cap when time allows. Thank you all...
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    Bad Capacitor?

    To quote myself in message #33, "I won't be able to test the board for a while. The location is deep inside my locomotive and it will take some time to access. I have several projects taking time. Thanks for your input." To access a cable for the board, I have to disassemble most of the...
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    How to properly connect wires

    I need to connect wires from the controller on my locomotive to the 2 motors wired parallel. There is one lead from the controller going to each of the motors. The circuit is protected with a 30a fuse and the motors are 7.5a each. The system is 24vdc. The wires are subject to movement as the...
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    DC MOTOR QUESTION

    Duke37 Thanks for the reply. The smaller wheels are on a separate truck. The two motors are on 2 axles on the same truck with the same size wheels. One motor was defective and replaced by the vendor/manufacturer. The new motor and balanced frame now works properly. Yesterday I ran 6.25...
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