Output buffer by IC 4050 If you want the circuit Output buffer for the circuit digital. I begs for to advise IC 4050 (Hex buffers with high-to-low level shifter inputs) because very be IC that be usable easily. use link up digital circuit TTL and CMOS well…..

Logic Probe by 74LS47 This circuit is a Logic Probe. It indicates the logic state of the node of any TTL logic circuit. To do that, we have to supply the probe with the same power of the circuit that we want to analyse: same Vcc and same GND. To check the logic level, we must connect the “Test” wire of the probe to the desired node of the circuit that we want to check….

Pulse Reading Logic by 74LS00 and 74LS123 This circuit is supplied as a hobby project. It uses indicator LEDs to display various logic states for high, low, rising pulse, and falling pulses. It can be used as a general troubleshooting tool and is particularly useful for debugging TTL and CMOS logic circuitry.
In this design, the first 74LS00 gate acts as a buffer for the input logic pin. The following gates invert the signal, then further buffer it for driving the designated high and designated low LEDs. …

LED 7 segment Count Down Alarm by PIC16F84 Here I have added two fets for the time-out switch, it is like an electronic relay, just much more reliable it can be used to sound a big horn, or what ever you like. PIC 16F84 running 4.00 MHz using crystal or resonator, not critical since this count down alarm only runs for a few minutes….

Counter display with led 7 segment by IC CMOS This is the simple counter circuit, the IC application number 4029 from binary data, and then sent to the IC number 4513, a driver IC 7 Segment, to show off a digital number from 0 to 9. When entering into a pulse signal input pin 15 of IC1, it will signal to the output signal is Binary.Then send the output from the pin Q0, Q1, Q2, Q3, and the pin. 6, 11, 14 and 2 of IC1.Go to the input of IC2 No….

Static 0 to 9 display by SN7446
The circuit shown here is of a simple 0 to 9 display that can be employed in a lot of applications. The circuit is based on asynchronous decade counter 7490(IC2), a 7 segment display (D1), and a seven segment decoder/driver IC 7446 (IC1). The seven segment display consists of 7 LEDs labelled ‘a’ through ‘g’. By forward biasing different LEDs, we can display the digits 0 through 9. Seven segment displays are of two types,