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I'm trying to build a half adder with soft-latching buttons as input, using only transistors. I looked up online for some ideas and managed to build a soft-latching input circuit and a half adder circuit on a breadboard. Separately they worked, but the output LED was dimmer than I expected. However, once I assembled the whole thing together, it seemed not to be working at all. I'm guessing that the current levels are too low to drive the components properly. With the breadboard I used a 3.2V battery.

Below is the design that I came up with. I'm not sure if it just missing some details or if I got the design fundamentally wrong. I would appreciate any hints or maybe recommendation for some reading that could help me understand this better.

Circuit

Edit

I applogize about the earlier schematic, here is one that I created earlier with Eagle, hopefully that will be better. enter image description here

Rafał
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    Now that's a schematic I absolutely must save as an example of why one needs to learn how to draw! Anyway, look at this [RTL XNOR](https://electronics.stackexchange.com/a/491990/38098) and, more closely to what you want, this [RTL Full-Adder Design Process](https://electronics.stackexchange.com/a/281320/38098). – jonk May 26 '20 at 14:41
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    Rafal, simple rule: when drawing a schematic, use horizontal and vertically aligned components only, This schematic is a mess. Also, a schematic needs to show compnent names. How else will we talk about it? "The 1 kΩ resistor blablabla" isn't really helpful. – Marcus Müller May 26 '20 at 15:08
  • What are those little open circle components? Why didn't you use 5V as shown on the schematic? – Elliot Alderson May 26 '20 at 19:32
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    I've updated the question with a more appropriate schematic. I used CircuitJS1 to try to understand better what was going on with the design and circles is how it represents LED (the inside changes colour when it's on). – Rafał May 26 '20 at 23:29

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