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# HarryA

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1. ## TENS machines revisited

Hello from NE PA, A question for you. How to TENS machines generate 40 to 60 volts from say 4.2 volts without using a coil or transformer? Pictured is a TENS circuit that is about 1.26 inches by 1 inch. The battery is on the reverse side of the board. thanks in advance, HarryA
2. ## 11.1 volts to 8.0 volts ?

I picked up some LM317's today (1.5 amperes max.). Set the output to 7.0 volts and connected to a brushed motor. The motor drew 0.68 amperes. The output voltage dropped to 6.86 volts; the li-po battery output drop to 11.55 from 11.80 volts. This is with no load on the motor; I need to get propeller on it. Someday I will receive the ESC and can reverse the motor on the fly. :)
3. ## 11.1 volts to 8.0 volts ?

Thanks. I replaced my diagram with the one from Motorola before seeing yours. I have power transistors coming from my favorite store - ebay. ;)
4. ## 11.1 volts to 8.0 volts ?

My "bright" idea is to use the mosfet to get more than the 1 ampere that the 8 volt regulator is rated at. I have a large 11.1v li-po battery for the main motor so I don't want to add another battery to get the 8 volts. I wonder if one can put two or three regulators in parallel for more current? This current is the power supply for the speed controller; it connects to the receiver for the PWM. It is the brushed type used with rc cars so it can reverse the motor for left and right control.
5. ## 11.1 volts to 8.0 volts ?

Hello all, I need to connect an 8 volt electronic speed control to an 11.1 battery. I have an 8 volt regulator and a power mosfet. I have not worked with mosfets before so I am puzzled on how to make the connections and what values of resistors are required. Please take a look at my diagram. Any advice would be appreciated. This motor control is for the stern of a model blimp to control the direction much like a helicopter's directional control. see:
6. ## Checking new PC power supply

Thanks guys. That's what I needed to know :) I made a tester out off a 12 v brake light and a 6 volt one ;)
7. ## Checking new PC power supply

I have a new power supply that I would like to check before installing into the computer. On bench testing it I get no voltage at all. Is thid correct? I am thinking that perhaps there is some type of interlock so you only get voltage when it is installed? thanks in advance.
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