Timeline for How to drive 700mA LED cheaply?
Current License: CC BY-SA 4.0
16 events
| when toggle format | what | by | license | comment | |
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| May 11, 2021 at 18:26 | comment | added | hacktastical | No, not as well. This one has a 1.23V reference so it won't do as good a job as a constant-current driver. | |
| May 11, 2021 at 18:21 | comment | added | maurera | Would this "3W 5-35V LED Driver 700mA" work? The 700mA current sounds correct, but I'm not sure about the voltage. I only need 1.5v forward voltage aliexpress.com/item/32825274876.html | |
| Apr 19, 2021 at 15:27 | comment | added | maurera | @MicroservicesOnDDD - it's plugged in. I use a AC-USB adapter (5v) with a micro usb cable plugged in to a microusb breakout board, which is wired to the circuit. | |
| Apr 18, 2021 at 21:41 | comment | added | MicroservicesOnDDD | @maurera -- If you are going to use only one LED, and not two in series, just be aware that for the Diodes Inc PAM2804 datasheet, the efficiency curve is for a white LED at around 3.3 volts (it's obvious from the graph). But your efficiency with only one LED is going to be significantly lower. Suggest going with two LED's in series, since you're getting a quantity of 10. What is your power source, by the way? Is it a battery, or is it plugged-in? With 3 LED's in series, a linear solution might be okay and may be efficient enough (with the right power source). | |
| Apr 18, 2021 at 15:12 | vote | accept | maurera | ||
| Apr 17, 2021 at 19:15 | comment | added | hacktastical | You’d add a series resistor between the sense pin and sense resistor, sized accordingly. This would cost practically ... nothing. Same thing with a digipot, or a PWM low-pass injected into that point. | |
| Apr 17, 2021 at 19:09 | comment | added | Andrew Morton | It might be worth pointing out that as the Maxim DS4432 has a maximum output current of 200 μA, more components, to make a DC-DC convertor, will be needed, so the cost would not be just $1. | |
| Apr 17, 2021 at 15:15 | comment | added | Daniel Chisholm | @Maurer try digikey.ca, I see CAD0.74 for the part and CAD8 shipping (for under-$100 order) | |
| Apr 16, 2021 at 22:04 | comment | added | hacktastical | You can sometimes request samples. But, yes, ordering onesey-twosies of anything can get expensive, fast. | |
| Apr 16, 2021 at 21:58 | comment | added | maurera | Thanks for this suggestion! 15 cents is certainly cheap - it's just $20 USD shipping to Canada that makes it expensive. I'll have a search on aliexpress for your suggestion of "LED driver IC". In my original post "expensive" referred to something like this for $7 - ledsupply.com/led-drivers/… (I'll clarify that in the original post) | |
| Apr 16, 2021 at 21:22 | history | edited | hacktastical | CC BY-SA 4.0 |
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| Apr 16, 2021 at 21:05 | comment | added | user57037 | That PAM2804 looks like it will do the job nicely. | |
| Apr 16, 2021 at 20:57 | history | edited | hacktastical | CC BY-SA 4.0 |
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| Apr 16, 2021 at 20:09 | history | edited | hacktastical | CC BY-SA 4.0 |
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| Apr 16, 2021 at 19:58 | history | edited | hacktastical | CC BY-SA 4.0 |
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| Apr 16, 2021 at 19:47 | history | answered | hacktastical | CC BY-SA 4.0 |