Recent content by David Lacroix

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    Trying to make a transistor cancel another transistor

    Thx again for all the tips! I do appreciate everybody taking on their time to draw schematic, it helps a lot! As for the LM3914, I think I'm going to start slow with transistors, I want to stay as analog as I can and I would like to do all my wiring in the case something is wrong I made it all...
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    Trying to make a transistor cancel another transistor

    Ok, so let's say I've got 10k NTC thermistor feeding the base of all 8 transistors connected in series to the LEDs. What I thought of, would be to have different increasing rating of resistors on the base of these transistors so when the first blue LED lights up, meaning it's goddamn cold, the...
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    Trying to make a transistor cancel another transistor

    Probably, around 4.5 Volts from 3 AA batt in series. How voltage would determine the wiring?
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    Trying to make a transistor cancel another transistor

    Hey guys, Thank you very much for all the quick responses! This was a learning experiment, I just started playing around with the most simple components so I might be a bit slow to get all that stuff. The idea behind it was that I thought of a complete project, other than just doing little...
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    Trying to make a transistor cancel another transistor

    They are resistors before LED and on transistor bases, they're just not on the drawing, which I made for myself to have a complete view of my layout.
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    Trying to make a transistor cancel another transistor

    I manage to make something work. Basically, transistor 1 will only work if transistor 2 is activated, which then can send current to the base of the third transistor which this one permits the number 1 to complete it's circuit. PrettyI know this must be pretty basic stuff but trust me I...
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    Trying to make a transistor cancel another transistor

    Hi, I tried making a circuit with 2 transistors as switches with an LED in which the first one would be cancelled if the second one is switched one. I thought about giving positive current to the negative of the one I want to cancel to make no difference in potential. Hasn't work yet, can't...
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    NPN transistor as switch for LED problem

    I'm going to try this next time and see what happens.
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    NPN transistor as switch for LED problem

    I guess I've probably toasted those transistors. I've just started playing around with electronics, I'm at step 1 haha...damn ps: when a transistor is toasted, could it conduct current straight from collector to emitter without anything from base, because that would answer some questions about...
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    NPN transistor as switch for LED problem

    What is a moderate value for you?
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    NPN transistor as switch for LED problem

    12V from 8 AA batt. Circuit is 12V to 220ohm to LED to collector then emitter to ground and then 12V to 100ohm to base.
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    NPN transistor as switch for LED problem

    Hi, I used an NPN transistor as a switch to light up a small LED. The circuit works great but when I cut the base current for the transistor the LED stays lit just a tiny bit. I'm using a 220 ohm resistor for the LED and a 100 ohm for the base of the transistor. What causes this? Thx
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    Small DC motor powering another DC motor to generator

    Hi, First of all, I'm a total noob. I've just started to light up LEDs with transistor and some other sensors. I've got just about the most basics skills. Alright, so I bought some super small permanent magnet DC motors and I had the idea to connect them both with a pulley and belt system to...
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