Need help stepping down voltage to LED strip

[awaisnasir98]

Hi, im trying to create a battery powered desk lamp with a flexible LED (3V, <300mA). I'm using a TP4056 charging module with a 3.7V battery.

Components:
1.TP4056 3.7V charging module
2. 3.7V lithium battery
3. Flexible LED filament
4. Touch sensor button (2 wire input, 2 wire output) with DIMMING FUNCTION
5. AMS 1117 module to step down the voltage

I have attached the wiring schematics below.

Problem: if i add the ams module at the output, it is continuously working and drains power from the battery causing the battery to die in 2-3 days. If i add it after the touch switch then problem is resolved but i loose the dimming functionality.

Can someone please provide suggestion on how can i reduce the voltage supply with any power loss while still keeping the dimmer function

 

[Harald Kapp]

The AMS1117 has a quiescent current of up to 10 mA. That's why your battery is drained.
The AMS1117 is a voltage regulator, but LEDs need a controlled current. The most simple circuit woulkd use a series resistor instead of the voltage regulator. With no quiescent current when the LED is off.

For more detailed help we need either datasheets of your components (links only, please) or at least the full component type (make, model, manufacturer) so we can look up the required details.

 

[awaisnasir98]

How many ohm resistor in series would be fine if I don’t use the AMS in between. One thing to note that the cut-off voltage for the charging module is 4.2V which is quite high. Below are the links i could find. Please let me know if they provide the relevant information.


LED filament
https://www.mouser.com/catalog/addi...T*MTcxNjQ3MDYxMC4xLjEuMTcxNjQ3MTg0Ny41OC4wLjA.

TP4056
https://hobbycomponents.com/power/903-ams1117-33v-power-supply-module

Lithium polymer 3.7 V 195mAh

Touch switch:
Could not find datasheet or detail on this but product description says:
Fit for Constant voltage adapter, don't fit for Constant

https://a.aliexpress.com/_ooyMIEG

 

[Harald Kapp]

How many ohm resistor in series would be fine

The LED strip works from 3 V. The powre supply outputs 5 V. The voltage difference is 2 V.
The LED strip requires 80 mA. From [imath]R = \frac{2 V}{80 mA}[/imath] we get [imath]R = 25 \Omega[/imath].

The wiring is:

5 V -> touch switch -> resistor -> LED strip

 

[bidrohini]

When the AMS1117 module is connected directly to the battery, it continuously draws power, causing battery drain even when the LED is off. Placing it after the touch switch solves the power drain issue but interferes with the dimming function. The AMS1117 has a relatively high quiescent current. Consider using a low quiescent current LDO (Low Dropout Regulator) which would minimize power loss when the LED is off. For example MCP1700.

You can also try a LM2576 Buck Converter instead of AMS1117 to see if your circuit performs better.

LM2576 Buck Converter Datasheet, Pinout, Features & Applications - The Engineering Projects

In this post today, I’ll walk you through the Introduction to LM2576. LM2576 is a step-down voltage regulator, also known as a buck...

www.theengineeringprojects.com