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 to Use Transistors
If you have understood correctly, how to use transistors in circuits, you might have already conquered half of electronics and its principles. In this post we make an effort in this direction. Introduction Transistors are 3 terminal semiconductor devices which is able to conduct relatively high power across their two terminals, in response to a […]
How to Switch Two Batteries Manually using Opto Coupler
The following article explaining a dual battery changeover relay circuit was requested by Mr.Raja so that it could become possible to switch between his old and new inverter batteries automatically, eliminating manual interventions. Let’s read it in details. Technical Specifications “I bought a new 12v 110 Ah lead acid battery for the dc home lighting system. I had another 12v […]
AC Light Dimmer Circuit
In this post I have explained through two examples how to build a simple110 V or 220 V AC light dimmer circuit for controlling light intensity with pot, using the principle of triac phase chopping. A 220V dimmer switch circuit is basically a triac/diac based AC mains voltage regulator circuit which can be used for […]