![]() ![]() ![]() It still plays when I lower the voltage, all the way down to 1.8 V but then it's barely audible - below 3 V is not gonna cut it, I'm afraid). (The device/load is a gag-birthday card which plays music at a rather annoying volume it comes with 3 LR1130 batteries, 3 x 1.2 V = 3.6 V and using my bench supply I measured it using about 100 ~ 200 mA - I just want to control when it plays. ![]() My main question is: What can I do to get close(r) to the desired 3.6 V without using a ton of components? Add a dropper diode or two? Second: will this work at all? Does my reasoning make any sense at all? Using the 3.3 V is going to leave 2.7 V for the switched load, which is too low.This should drop around 0.6 V, leaving 5 V - 0.6 V = 4.4 V? This is a bit on the high side I'm afraid. I was planning on using a 2N2222 (but I have others) as my 'switch'.I need a 4k7 resistor to limit the current from the datapin (D4).Since a Wemos D1 pin can only handle about ~12 mA I need to use a transistor to switch the required 0.1~0.2 A. All is powered by an 18650 shield that outputs both 5 V and 3.3 V. NPN switching transistors, 2N2222 Datasheet, 2N2222 circuit, 2N2222 data sheet : PHILIPS, alldatasheet, Datasheet, Datasheet search site for Electronic Components and Semiconductors, integrated circuits, diodes, triacs and other semiconductors. I want to be able to toggle the power to this device with a Wemos D1 mini (sadly, represented below as an Arduino since I can't find a Wemos in ). In the below schematic it's represented as a speaker. P2N2222A Amplifier Transistors NPN Silicon Features These are PbFree Devices. that draws about 0.1~0.2 A and requires 3.6 V. ![]()
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