Electronic Basics #2: Dimming all kinds of LEDs?
video description
Im using this circuit to dim 10 lasers that are hooked up in parallel.
The input voltage of the circuit is 5. 0v from a computer power supply.
So here is where it gets weird. with a single laser installed, the dimmer works flawlessly. I add a second, and the output voltage jumps up to around 8 volts, and the when i adjust the potentiometer, the lasers dim at different rates. One dims out before the other starts to dim.
I now have 6 out of the 10 lasers hooked up, and the output voltage is now at 19. 56 volts. One of the lasers is running very dim, while the other five lasers are full power. The five lasers are dimming near the same rate, but the one that is already dim turns off completely.
I have no idea why the output voltage keeps increasing with every laser i add.
Is it just a simple case of using the wrong mosfet? Or is this circuit simply not going to work for what i need?
Thank you to anyone who offers any helpful advice!
Date: 2020-09-05
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Comments and reviews: 8
B. W.
Dear Great Scott. I like your explanation but. I have a desing question that up to now I have not been able to solve. I want to dim a low power LED (in this case a bicycle rear-light LED. The dimmed state would be the normal operation state. When I apply the brakes I want the LED to become brighter (i. e. brake-light. That should be by the use of a momentary switch. I do not like the solutions with resitsors and diodes. Ik was hoping you or someone like you would have designed such a solution around a 555 chip for insance. Maybe there are already better IC's for this I do not know. Could you device such a schematic?
I would be very interested.
Thanks in advance for your efforts and educational youtube postings which I am enjoying very much.
reply
Dear Great Scott. I like your explanation but. I have a desing question that up to now I have not been able to solve. I want to dim a low power LED (in this case a bicycle rear-light LED. The dimmed state would be the normal operation state. When I apply the brakes I want the LED to become brighter (i. e. brake-light. That should be by the use of a momentary switch. I do not like the solutions with resitsors and diodes. Ik was hoping you or someone like you would have designed such a solution around a 555 chip for insance. Maybe there are already better IC's for this I do not know. Could you device such a schematic?
I would be very interested.
Thanks in advance for your efforts and educational youtube postings which I am enjoying very much.
reply
David
Im trying to wire a brake light/marker light on to my car. Im going to cut into the tail light wires and bring two positive wires to the new light. One being tail marker, and the other one brake light.
So the light i bought only has a brake light on a single wire.
I was wondering if i could wire in a resistor to the tail light wire to make it come on with tail lights dim and full power on brake light. Can you help me identify what parts i need to complete this project? And so i dont backfeed power because the two wires will have to connect to the single wire. And tail light will always be on unlike the brake light.
Thank you for your time!
reply
Im trying to wire a brake light/marker light on to my car. Im going to cut into the tail light wires and bring two positive wires to the new light. One being tail marker, and the other one brake light.
So the light i bought only has a brake light on a single wire.
I was wondering if i could wire in a resistor to the tail light wire to make it come on with tail lights dim and full power on brake light. Can you help me identify what parts i need to complete this project? And so i dont backfeed power because the two wires will have to connect to the single wire. And tail light will always be on unlike the brake light.
Thank you for your time!
reply
Supertyp
Hey Scott can you make a PWM video where you explain, how PWM can be used to convert digital signals to analog without an DA converter? Always wanted to undestand that. It's somehow that you change the pulse with in a way that it creates a near sinus analog wave.
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Hey Scott can you make a PWM video where you explain, how PWM can be used to convert digital signals to analog without an DA converter? Always wanted to undestand that. It's somehow that you change the pulse with in a way that it creates a near sinus analog wave.
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Hossein
I just learned some about PWM but i still don't know how to diy a pwm or how it works. But i guess dimming one led is basic but dimming multiple of them is advance.
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I just learned some about PWM but i still don't know how to diy a pwm or how it works. But i guess dimming one led is basic but dimming multiple of them is advance.
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LarixusSnydes
I like most of your videos, but this is far beyond the basics. You go much too fast and you integrate principles and devices you have not introduced before.
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I like most of your videos, but this is far beyond the basics. You go much too fast and you integrate principles and devices you have not introduced before.
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GhOsT
Dude! this too hard for beginners TT OMG i know some basics and i find myself struggle learning this. I get the idea but not full understanding: '(
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Dude! this too hard for beginners TT OMG i know some basics and i find myself struggle learning this. I get the idea but not full understanding: '(
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Michael
If i use pwm will it be visible when I record it. Like recording with a 60hz camera somewhere where there is 50hz current (flickering?
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If i use pwm will it be visible when I record it. Like recording with a 60hz camera somewhere where there is 50hz current (flickering?
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Jun
Hey sir scott. what frequency you often use on your circuit? Like that dimming circuit and the boost and buck converters
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Hey sir scott. what frequency you often use on your circuit? Like that dimming circuit and the boost and buck converters
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