Circuit-Zone.com - Electronic Projects
Posted on Wednesday, November 16, 2016 • Category: Test and Measurement
I finally got round to making my capacitor ESR tester this week after finding a nice simple 5 transistor version. Unfortunately, for me, the design was only SMD so, I decided to replicate his schematic in Eagle PCB using a through hole component design. I will not be going into much detail regarding ESR or Equivalent Series Resistance Meters as, there is already plenty of other sources of information on the subject. Yet, every tinkering knows capacitors are guilty of a lot of sins in electronics. Capacitors love to throw red herrings! They can appear physically fine (no bulge), show good capacitance and hide in circuit, standing to attention like the Queens Guards hiding shorts and high resistance under their big hats. This is where the ESR tester can be a saviour, with the ability to test for "out of specification" high resistance, within the capacitor. They can also be used to test "in circuit", without the need to remove every capacitor in the circuit.
Posted on Sunday, October 30, 2016 • Category: FM Transmitters
The above FM transmitter has RF output power of 300 mW and covers more than one kilometer distance. Frequency adjustment is accomplished with MV2105 varactor diode and R7 10K potentiometer. 2SC2538 is a class C 300mW amplifier.
Posted on Monday, October 24, 2016 • Category: FM Transmitters
High performance low noise 500mW amplifier / booster for all low power FM transmitters such as BA1404, BH1417, BH1415, 433MHz transmitter modules, etc. The amplifier chip is an integrated circuit containing multiple transistor stages and all other parts conveniently within a single small package. Boosting your FM transmitter has never been easier and the output signal can also directly drive 2n4427 or 2n3866 transistors for 1W or 5W of RF output power.
Posted on Friday, October 21, 2016 • Category: FM Transmitters
The power amplifier boosts 88-108MHZ 1-2W FM transmitter's power to 15 W. It includes multi-level low pass filter and has a high conversion efficiency with strong Yi-wave suppression. With good antena expected transmission coverage is at least 15Km. It uses high power 175 MHZ 4A 25W 2SC1972 RF transistor that must to be mounted to heatsink for proper heat dissipation.
Posted on Friday, September 30, 2016 • Category: Power Supplies
Solar energy is renewable, free, widely available and clean form of energy. It is considered as a serious source of energy for many years because of the vast amounts of energy that is made freely available, if harnessed by modern technology. Many people are familiar with so-called photovoltaic cells, or solar panels, found on things like spacecraft, rooftops, and handheld calculators. The cells are made of semiconductor materials like those found in computer chips. When sunlight hits the cells, it knocks electrons loose from their atoms. As the electrons flow through the cell, they generate electricity.
In this project, we are building a power bank which harvests energy by using a solar panel. The energy gained by the solar panel is stored in a LiPo battery. Then the battery is used to supply a stable 5V which is used by USB gadgets. The power bank can also be charged by an external 5V source. The best thing for this power bank during day that you donít need to remember to charge it. It charges itself by using the sunlight and you donít come up with an empty bank.
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