A four-bit adder adds two 4-bit binary numbers (one number 0-15 in decimal notation) Works on transistor logic. The number is entered by using an 8-pin DIP switch, the first 4 switches are the first number, the next one and up to the end are the 2nd number. There are 3 connectors on the left side of the board, two of them are signed as "9.5v" power connector and "GND". Third connector "J1" is a connector for reception the result from the transfer bit of the previous adder.

ATTENTION! The device consumes 2A when calculating the maximum number, do not connect to the computer connectors, this may harm it. Also, do not keep the device turned on for too long (more than 30 seconds), otherwise a breakdown is possible.

This device has no practical use and is intended to familiarize with the operation of logic elements on transistors and to develop soldering skills))