Trouble with slide switch and Lithium Ion Battery

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OsirisProps
 
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Trouble with slide switch and Lithium Ion Battery

Post by OsirisProps »

Hello! I'm new to the forums (this is my first post)!

I have a project I've been working on, and have run into an issue that I'm hoping I could get some help with. Recently, I purchased the Lithium Ion Polymer Battery - 3.7v 1200mAh (PRODUCT ID: 258, for reference) for a project I'm working on. It is powering a parallel circuit consisting of 3 LEDs with a slide switch to be able to turn them off and on. The LEDs are rated at 3.2 forward voltage, 20mA continuous current, with a 10 ohm 1/8 watt resistor.

The issue I've run into is with the slider switch. It's a SPST sub mini slide switch, with a contact rating of 0.5A at 30VDC. When the switch is in the circuit, and flipped to the on position, the LEDs are barely lit. If I leave the switch in the on position but break the circuit and reconnect it manually (which I just do by disconnecting/reconnecting the contacts from the battery), then the LEDs will light normally and as expected. Is it an issue with the switch not being able to handle the 1200mA? I saw a slide switch in the shop as well, but I'm hoping to pin down the issue before exploring other switch options. Thank you!

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adafruit_support_bill
 
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Re: Trouble with slide switch and Lithium Ion Battery

Post by adafruit_support_bill »

The 1200mA is not the issue since the current through the LED circuit is limited to 20mA by the resistor. If the LEDs are brighter when you bypass the switch, that indicates that there is some additional resistance in the switch which is limiting the current even further. If you have a multimeter, you should check the resistance across the switch. If it is more than a few hundredths of an ohm, it is likely a defective switch.

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