Timeline for Boost Converter Woes
Current License: CC BY-SA 3.0
20 events
| when toggle format | what | by | license | comment | |
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| Nov 17, 2016 at 20:19 | comment | added | Ale..chenski | One more question: did you make a little PCB with manufacturer's suggested layout (Fig.22 of TI specs), or did you do some breadboard prototyping? | |
| Nov 17, 2016 at 19:57 | answer | added | Andy aka | timeline score: 1 | |
| Nov 17, 2016 at 19:03 | history | edited | Bence Kaulics | CC BY-SA 3.0 |
added 48 characters in body
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| Nov 17, 2016 at 18:57 | comment | added | kevinconnectable | No, it is the output current of the LEDs. I attached my adjustable power supply to the circuit and powered it at 3.6v (draws .011A) and then at 7.6v (draws .09A) | |
| Nov 17, 2016 at 18:54 | comment | added | Barleyman | Incidentally, does your "11mA" and "90mA" refer to the INPUT current from battery or the OUTPUT current to LEDs? | |
| Nov 17, 2016 at 18:53 | answer | added | Ale..chenski | timeline score: 3 | |
| Nov 17, 2016 at 18:48 | answer | added | Barleyman | timeline score: 0 | |
| Nov 17, 2016 at 18:46 | comment | added | kevinconnectable | Ali, I did not, but I will definitely check them out! | |
| Nov 17, 2016 at 18:45 | comment | added | Ale..chenski | My bad, FREQ=gnd is correct, sorry. For LED driver, did you search thousands of SEPIC converters on Digi-Key. How about AP3031, with 200mV feedback sense? | |
| Nov 17, 2016 at 18:40 | comment | added | user76844 | For gnd upwards people go to hell | |
| Nov 17, 2016 at 18:40 | comment | added | kevinconnectable | Ali, the datasheet specifies the EN pin should be driven high to enable the device. The FREQ pin is pulled low to drive the IC at 650 kHZ. I would use a LED driver, but I am unable to find one small enough to fit my application. | |
| Nov 17, 2016 at 18:40 | comment | added | Barleyman | @AliChen Using LED driver for 0.35W LEDs is a huge overkill. I've got 1.2kW LED driver on my desk right now, that's a bit more appropriate application. Small currents and voltages like this, just use a series resistor. | |
| Nov 17, 2016 at 18:37 | comment | added | Ale..chenski | You should consider "LED driver". It makes no sense to waste power in a resistor, when a booster can give you quite better efficiency. | |
| Nov 17, 2016 at 18:34 | comment | added | Ale..chenski | To operate the IC at 400kHz, the EN pin must be grounded, not as shown. Your chip is running at 1.2MHz, and 6.8uH inductor might be too much. | |
| Nov 17, 2016 at 18:33 | comment | added | kevinconnectable | My plan was to use a resistor to limit the current. I have played around with different resistor values, but I just wanted to show that the converter is not outputting enough current with no means of current control. Perhaps I should use a different boost converter? (one with a constant current mode) | |
| Nov 17, 2016 at 18:30 | answer | added | owg60 | timeline score: 1 | |
| Nov 17, 2016 at 18:29 | comment | added | Ale..chenski | To begin, you are not feeding the LEDs correctly. The LEDs are supposed to be controlled by current, not voltage. You need to convert your circuit into current-feedback booster, as all professional LED drivers do. | |
| Nov 17, 2016 at 18:27 | comment | added | winny | How do you regulate the output to produce constant current? | |
| Nov 17, 2016 at 18:17 | review | First posts | |||
| Nov 17, 2016 at 18:38 | |||||
| Nov 17, 2016 at 18:17 | history | asked | kevinconnectable | CC BY-SA 3.0 |