Sometimes you have to do it the hard way, even if doing it the easy way is an option. That is the case here. The intention is to add a second doorbell in parallel with the existing bell. This does not, in principle, require any electronic components. You....

This simple 12VDC to 220VAC inverter circuit produces an AC output at line frequency and voltage. The 555 is configured as a low-frequency oscillator, tunable over the frequency range of 50 to 60 Hz by Frequency potentiometer R4. The 555 feeds its output....

This circuit enables observation of movement between other stroboscopes. Generation of rectangular signal is based on NE555. This circuit requires a low power supply that is made from a simple transformer TR1, traditional rectifier bridge and zener diode.....

Using high voltage transistors can be designed a DC power supply that can provide a supply voltage between 10 and 300 volts which can be adjusted with the potentiometer P1. Transformers typically used in such sources have several windings of high voltage and....

Q1, Q2 & Q3 form a high impedance super-Darlington that drives the relay, amplifying the 50 or 60Hz alternate mains-supply frequency induced in the sensor by the human body. C1, D2 & D3 ensure a clean switching of the relay. Power supply can be any....

Stabilized voltage inverter 12V-220V 200W is shown in the following diagram. It can adopt existing dual 12V-200W mains transformer. But its invert efficiency is low....

Another method of using opamps to regulate a power supply is shown below. The power transformer requires an additional winding to supply the op-amps with a bipolar voltage (+/- 8 volts), and the negative voltage is also used to generate a reference voltage....

A negative output voltage dc to dc converter generates a -5V output at pin A. In order to generate -5V at point A. the primary of the transformer must fly back to a diode drop more negative than -5V. If the transformer has a tightly coupled I : 1 turns....

It has an audio transformer. I`m still attempting to grasp the concept of impedance and such, so can someone explain why this is necessary And how would such a transformer even work to change the impedance What would be the difference if you didn`t use an....

A power supply project without using a power supply. This can save the expense of buying a transformer, but presents potentially lethal voltages at the output terminals. Under no circumstances should a beginner attempt to build such a project. Electric Shock....

This circuit is a small +5V power supply, which is useful when experimenting with digital electronics. Small inexpensive wall tranformers with variable output voltage are available from any electronics shop and supermarket. Those transformers are easily....

The circuit is intentionally designed using old type transistor, it is to get the harmonic distortion and to avoid the difficulty of finding good components. Amplifier (s) can be easily supplied by plug-in wall transformer 12V. Closing SW1 bass boost is....

The circuit given here is of a regulated dual power supply that provides +12V and -12V from the AC mains. A power supply like this is a very essential tool on the work bench of an electronic hobbyist. The transformer T1 steps down the AC mains voltage and....

A 40 watt fluorescent (tube lamp, TL) or two 20-watt tubes in series will be driven by this circuit. The transformer is wound on a ferrite rod 10mm dia and 8cm....

It uses very common building blocks. The high voltage power supply is a classical oscillator circuit used in many places where a low current and high voltage is needed. TR is a step-up transformer salvaged from a xenon light circuit. You can find simmilar....

2 versions. First is one based on your schematics, except that I`ve changed those smd capacitors for standard through hole ones. Second one is somewhat modified. I`ve excluded transformer and put in standard dc jack. Also, pic and display header are located....

This circuit have an advantage over ordinary CONTINUITY testing Device, usually we are using multimeter to check the continuity of a circuit. It is not suitable to check the continuity of a circuit with high Impedence or resistance like Transformer,....

This circuit can charge automatically, fast and rightly, batteries 6V and 12V. A basic factor in the success in the circuit operation is the use of transformer [T1] of good quality with very good insulation and resistance in the short circuits....

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We introduce an inverter today mainly by the MOS field effect tube, the ordinary power transformer forms. Its output power depends on the power of MOS field effect tube and power transformer, avoid the convoluted voltage transformer to wind, suit electronic....

Before I begin talking about the schematic, let it be known that there are four hardware blocks to this circuit: 1) The wall transformer 2) The charge....

If you don`t have an audio detector already constructed, you can use a nice set of audio headphones (closed-cup style, that completely covers your ears) and a 120V/6V step-down transformer to build a sensitive audio detector without volume control or....

Inexpensive miniature transformers normally provide one or two secondary voltages, which is sufficient for generating a set of positive and negative suppl....

A remote control light switch that fits into the existing light switch panel. And to power up the electronics that would requires a 3. 3V DC supply. The problem is, the panel has only two wires inside - 1. Live and 2. wires that goes to the light bulb. The....

Inverter of what this text produces see Fig. 1 Mainly by the MOS field effect tube, the ordinary power transformer forms. Its output power depends on the power of MOS field effect tube and power transformer, avoid the convoluted voltage transformer to wind,....

Most timer circuits. Often used with electrical transformers containing low as 9V and 12V, and use of electrical control relays.but the 1-15 minute timer....

Interfacing high power load can be done in many ways, such as using voltage divider resistors, transformer, or optocoupler. In the circuit shown below, an optocoupler method is presented. This optocoupler serve the logic level translation with flexible....

This simple amplifier does sound good quality Power output about 10 - 14 Watts with Supply voltage about 34 - 36 Volt DC. It requires a preamp in the function of it hasn`t got much advance. It requires cumbersome heat up sinks and a great transformer and a....

The concept behind the light dimmer is to control the voltage to the light lamp or any source. Light dimmers regulate the voltage to the source they are connected to. This regulation of voltage increases or decreases the light intensity. Light dimmers first....

the circuit has two-stage circuit structures, the timing time is about 0. 5~12s, and in figure (b), the range of the timing time is 1~160s. The parameters of transformer: iron chip: M42/15. 7 silicon steel sheet; winding: 0. 18mm, enameled copper wire....

This inverter circuit can offer a really stable 230V Output Voltage. Frequency of operation is decided by a VR1 and is generally set to 60 Hz. varied off the shelf  transformers can be used. Or Custom wind your own for best results. additional MosFets can....

The circuit is a DC to DC converter using a standard 12 VAC center tapped power transformer wired as a blocking oscillator. The circuit is not very efficient but will produce a high voltage usable for low power applications. The input battery voltage is....