In this article I have explained how to make any BJT or mosfet based circuit free from stray signal pickup and false triggering by simply attaching a filter resistor or a capacitor across their base/emitter or gate/source terminals. The problem was raised by Mr.Henrik. Solving a Circuit Problem I have an issue I don’t understand. […]
Newly Updated Circuit Projects:
LED Chaser Circuit using IC 74LS164: LEDs illuminate in Bar Mode then Shut off together or one by one
This circuit is actually a little more advanced LED chaser scanner circuit using two 74LS164 Shift Register ICs together with one NE555 Timer, and yep the light effect looks somewhat similar to those old Knight Rider or Mustang scanner lights which move from sides toward center. The LEDs are arranged in two strips, or sometimes […]
LED Chaser using IC 74C164: 8 LEDs turn ON one by one, Shut off, then Repeat
Referring to the following chaser circuit diagram below, we can see a low-frequency, astable oscillator circuit, made up of two gates, IC1a and IC1b, from the IC 4011 quad two-input NAND gate. The operating frequency of this astable is determined by the values of C1 and R11. This circuit configuration works well as a clock-pulse […]
BJT 2N2222, 2N2222A Datasheet and Application Notes
This article explains the main specifications, pinouts and application related information regarding the transistor NPN BJT 2N2222, 2N2222A, and also its complimentary PNP pair 2N2907 BJT Introduction In one of my earlier posts I have explained regarding a few low signal type of transistors like BC547, BC557 etc. Here we are going to study the […]
Proximity Detector IC CS209A Pinouts – Datasheet Explained
In this post I have explained the main specifications and pinout functions of the IC CS209A along with other technical aspecst of the chip. Introduction The device CS209A is a bipolar monolithic IC specifically designed for metal detecting circuit applications. The IC fundamentally has a built-in oscillator stage, a couple of current regulator stages, a […]
2N3904 Datasheet [40V, 200 mA NPN Transistor]
In this post I have explained the main datasheet and pinout details of the NPN transistor 2N3904 Introduction The transistor 2N3904 comes under the category of NPN small signal, low power, general purpose transistor, mainly applicable for switching and for signal amplification. It’s dynamic range may include a current handling capability of more than 100mA […]





