# Tag Info

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A dim LED can be powered from a button battery cell for a short time. I have some cheap solar garden lights that use a 1.2V AAA Ni-MH battery that is charged by a 30mA/2V solar panel all day. Its QX5252 IC is similar to yours but has an English datasheet and it lights a single LED or a colors changing IC brightly all night. My AAA battery is MUCH larger than ...

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I had a pretty similar circuit 2 months ago, using TP4056 with PAM. Since, you are getting the output voltage, only other fault could be coming from lack of current. I would check if Amperage and ESR of Inductor L1, are within specified tolerances (0.1 value of R1 will require atleast 1.5amp rated inductor, and LED you are driving requires a minimum of ...

2

The main problem is that you haven't designed a level translator: - It's a source follower and the voltage at the source will be approximately what is at the gate but about a volt lower in amplitude (MOSFET depending). It won't give a 5 volt PWM level translation. To do that you need the source connected to ground and a resistor from drain to 5 volts. This ...

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Previous question shows output of your battery box 31V. Feed 4.5V, so it has step-ups voltage converter inside. You may connect your wall cube power supply output to battery holding springs. Just make sure it is right polarity. Or use some supply with 31V output. Polarity is important too. Reversing polarity may cause damage.

1

You need an led driver that can provide 700mA at 13V. Constant current drivers typically have a voltage range in which they can provide the specified current (often refered to as "constant current region"). That's like with a CV power supply, which has a specific current range in which it can provide the nominal voltage. While the rated current for ...

1

The LEDs must be connected in series strings of LEDs. A string of 8 LEDs would work, with a single small resistor to linit the current. Connect ten strings in parallel, and you have 80 LEDs. Alternatively, connect eight strings of ten LEDs, and rely on current limiting in the power supply. This will work if the LEDs in the strings are all matched. For ...

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The usual solution to control lots of RGB LEDs is individually addressable LEDs like WS2812B. I believe these have a PWM frequency of 400Hz, so perhaps addressable LEDs based on a chip like GS8208, which has a PWM frequency of 8kHz, would be preferable. Since each LED has its own free running oscillator, they won't be synchronized. The frequency of each LED ...

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Depending on what's sourcing the PWM, you can push the frequency up into the kilohertz range and if you STILL need per-LED smoothing after that you can use a simple RC filter with the resistor that's almost certainly already there to limit LED current. Not good enough? Filming with high-speed cameras? LEDs will handle megahertz PWM, but that's not cheap any ...

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You can boost with a regular DC-DC step-up buck converter. Like this one on Ebay It can deliver up to 5A. Which is bigger than your need, it should sufficient enough to hold your LED bright :) And furthermore is under \$5 :)) You can search like that at almost every e-commerce like eBay, Aliexpress, Bangood, Amazon etc.

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Here is a PMOS based solution since you have common cathode LED's. The logic is not really right. You will have to re-arrange which LED's are connected to which MOSFET. Basically, the MOSFET will be turned on when you drive its gate low. All the LED's connected to that MOSFET will be turned on when the MOSFET is turned on. simulate this circuit – ...

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if for some reason you need to short the LED current instead of switching it you could fix your circuit by using one MOSFET for each resistor and interconnecting the gates instead of interconnecting the resistors. simulate this circuit – Schematic created using CircuitLab

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This is one way to do it. This inverts the logic compared to what you have now. What I mean is, in your current circuit, driving the gate high turns OFF the relevant LED. But in my circuit below, driving the gate high turns ON the relevant LED. When the LED's are off, the drain of the MOSFET's are basically at VCC. When the LED's are on, the drain is ...

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That is a pretty weird way of "driving" LEDs. OP's schematic: A few issues: essentially you have an "equivalent" resistor, shared by the LEDs (if the LEDs have any imbalance - which they have - the current draw will be uneven) power draw - when the LEDs are "off", the FET will be drawing the current (even more than the amount ...

6

Yes, it requires modifications. First of all, the LEDs of different colors are in parallel, so only LED with smallest Vf will light up. And connected like that, the resistors get paralleled too, so you have much more (3x what you intended?) current flowing via the LED that does light up. Even more, the LEDs are turned off by shunting current by turning FET ...

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