The common problem with many low cost inverters is their incapability of adjusting the output voltage with respect to the load conditions. With such inverters the output voltage tends to increase with lower loads and falls with increasing loads. The circuit ideas explained here can be added to any ordinary inverter for compensating and regulating […]
Archives for 2012
How to Make LED/LDR Opto Coupler
Ever needed an application where the resistance of a resistor needed to vary proportionately in response to a PWM or a varying analog voltage? Yes, this is where an LED-LDR opto-coupler becomes so useful. The following image shows the symbol for a LED LDR opto-coupler. Any other regular opto-coupler, such as an LED/transistor, LED/FET, or […]
Simple LDR Motion Detector Alarm Circuit
Here I have explained how to build a simple LDR based motion detector sensor circuit using ordinary parts such as LDRs and opamps, reasonably accurately. What are Motion Detectors Motion detector or sensor alarm is a device which detects the presence of a motion or movement within a certain fixed range and raises an alarm […]
How Switch Mode Power Supply (SMPS) Circuits Work
SMPS is the acronym of the word Switch Mode Power Supply. The name clearly suggests that the concept has something or entirely to do with pulses or switching of the employed devices. I have explained how SMPS adapters work for converting mains voltage to a lower DC voltage. Advantage of SMPS Topology In SMPS adapters […]
Cheapest SMPS Circuit Using MJE13005
The explained circuit in this article is probably the simplest and the cheapest, since it employs minimum number of components and the making of the circuit is very straightforward. Circuit Operation Generally SMPS topology involves some fixed standard stages and criteria. Thgey may be listed in the following manner: The first stage which is the […]
Simple Programmable Timer Circuit
This programmable timer can be used for switching a load ON and OFF with two sets of time delays, which are programmable from 2 seconds to 24 hours independently. The delay timings are adjustable according to the users personal specs. The ON time delay and the OFF time delay are independently settable and this facility […]





