Electronics Design

Sine wave inverter technology

An ideal power inverter will produce same kind of power that is available from mains outlet, which typically means sine waveform 60 Hz 11-120V AC or 50 Hz 220-240V AC. That kind of power source can power all mains powered devices as long as enough power is available. Where power inverter devices substitute for standard

Modified sine wave inverters

This is a continuation to my Power inverter designs post. The first post was about general details of inverters and square wave inverters. Because square wave inverters are not suitable for many applications. The next better inverter category is so called modified sine wave inverter. Modified sine wave inverters are less complicated than sine wave

PoE Powered Christmas Lights

Found some broken LED christmas lights (operated originally from 24V transformer) and a suitable spare switch mode power supply (36-72V to 24V). Then I got an idea to combine them to an experimental PoE Christmas light project. Circuit diagram: The circuit operation: Initially circuit presents around 23 kohms impedance when low voltage is on line

Power inverter designs

A power inverter, or inverter, is a power electronic device or circuitry that changes direct current (DC) to alternating current (AC). The inverter does not produce any power; the power is provided by the DC source. This document is collection of information on power inverter technology and gives links to DIY circuits – both good

50 ohm vs 75 ohm conversion

Coaxial cables are measured by impedance. The most common impedance values are 50 ohms and 75 ohms. different cables. 50 ohms is most often used for radio transmitting and receiving applications. 75 Ohm is primary used for video and audio. 75 Ohm cables are the standard coax cable you find everywhere inside your home and

Calibration of multi-meters

I saw this question posted to ELECTRONICS HOBBY CIRCUITS IN FACEBOOK group: “can you tell me what is the meaning of calibration date of a multimeter and does it effect the work of a multimeter if it expires the calibration date?” The answer to this is: As all circuits will drift with time, the DMM

Capacitor testing

Test with multi-meter that it is not short circuited. Test with capacitance meter that capacitance value is correct. If this is an electrolytic capacitor I measure ESR. With some electrolytics I charge them to nominal voltage with power supply and measure charging leakage current or the rate it self duscharges. If it is a small

Short circuit protection

Facebook post at https://www.facebook.com/groups/electronichobycircuits/permalink/3743513689006646/ advertises this circuit idea: Amazing Idea With Relay & BC547 Transistor https://techsawco.com/amazing-idea-with-relay-bc547-transistor/ I see this circuit much less than amazing. “This circuit is used as voltage level indicator and short circuit protection circuit.” Voltage level indicator idea is feasible. The “short circuit protection circuit” does not live up to the promises

ESR meter DIY

One way to test electrolytic capacitors is to measure their capacitance. It does not tell the whole story of capacitor condition. Another usually more useful way to measure electrolytic capacitor condition is to use an ESR meter. Here is ESR meter I built years ago based on instructions from http://ludens.cl/Electron/esr/esr.html but I built the transformer