This circuit is basically a simple yet extremely accurate push button monostable timer using one half of a CD4538 dual monostable multivibrator IC. It works as a one-shot timer, where one press and release of S1 produces one timed output pulse. This pulse turns ON the BC557 transistor and the LED for around 7 seconds, […]
Timer and Delay Relay
Delay based Motor Speed Controller Circuit – Timer Controlled
In this post I have explained a delay OFF adjustable motor controller circuit so that the motor can be assigned a fixed predetermined operating time, or delay OFF time. The idea was requested by Mr. Cribey Technical Specifications I really like your website. It is very helpful for so many people. I am trying to […]
Long Duration Timer Circuit using IC 4541: Working and Calculations
The CD4541B is a CMOS programmable timer IC, and we use it where long delay interval is needed for a load, and also for jobs like frequency division, or timing pulse work. And all this happens with only just a few outside parts, not much around it. With ordinary IC 555, when delay becomes too […]
Automatic Door Lamp Timer Circuit
In this article I have explained a simple automatic door light timer circuit which activates every time the door is opened, and switches OFF after a predetermined time if the door is kept open for too long. The circuit was requested by one of the avid readers of this blog, Mr. Juan. I have explained more. Technical Specifications: I always find […]
Timer Based Cell Phone Charger Circuit
A simple cell phone charger with timer circuit is presented in the following article, which could be used for charging a given Mobile phone for a specified predetermined length of time. The idea was requested by Mr. Saad. Circuit Objectives and Requirements Could you design me this charger circuit ? Input 230V 60 Hz, and the […]
LCD 220V Mains Timer Circuit – Plug and Play Timer
In this post we are going to make an LCD 220 V mains operated timer using Arduino whose countdown time can be witnessed via 16 x 2 LCD display. Introduction The proposed LCD timer circuit is general purpose timer with display and few buttons for setting the time. Once the time is set output goes […]