The first section of the 555 timer is wires as an astable oscillator with R2 and C1 setting the frequency. The output is available at pin 5. The second section is wired as a phase inverter. That output is available at pin 9. Resistor R3 and R4 keep output transistor Q1 and Q2 from loading down the oscillator.

The two transistors drive the transformer push-pull fashion. When one transistor is biased-on, the other is cut-off. The transformer is a 120V/18V center tapped that is connected backwards, so that is steps the voltage up rather than down. Oscillator circuit U1, R1, R2 and C1 operates from about 4 to 6V with very stable output.

Components List:

The above inverter circuit converts 12VDC to 220VAC with power of about 50W. To circuit consists of the oscillator around the IC1, a divider IC2, an unstable polydoniti IC3, which gives the output of a symmetrical rectangular signal frequency 50HZ, followed by a buffer stage with Fet Q1-2, the driver stage and Q3-4 the power stage Q4-5, power transistors Q5-6, should be placed on a heatsink .. diodes Zener D2-3 protect the power transistors from voltage spikes produced by the transformer T1.

The transformer T1 are a simple power transformer with a medium shot, which is connected to the contacts of CO1. To use the wish, o T1, is placed upside down, with the secondary winding be used as primary, with the receiving means being connected to the positive battery voltage is 12V and the two other contacts are connected to the emitters of Q5-6, the connected to earth potential alternately, depending on the rate set by the outputs 10 and 11 of IC3. In this manner while flowing in the primary alternating current generated in the secondary alternating rectangular voltage 220V.

Using crystal oscillator ensures very good reference frequency 50HZ, and use a common crystal (CR1). For greater accuracy in parallel with C1, a variable capacitor CCH ensuring the adjustment of the frequency, in order to obtain the point P1 frequency 204.8 KIZ. It is evident that the output voltage at no-load is higher than the voltage under load. Also, the output voltage depends on the battery voltage. Thus for 14V battery voltage, the output voltage is increased by 10%, compared with the battery output voltage to 12V. If the converter works in load power 40 until 60W, then it can be used 2CH9V transformer. Various output values ??for battery voltage 12V transformer and 2CH10V.

50W Inverter 12VDC to 220VAC PCB Design:

50W Inverter 12VDC to 220VAC Component Placement:

circuit source

Basic Inverter Components list:

Notes:

1. Q1 and Q2, as well as T1, determine how much wattage the inverter can supply. With Q1,Q2=2N3055 and T1= 15 A, the inverter can supply about 300 watts. Larger transformers and more powerful transistors can be substituted for T1, Q1 and Q2 for more power.

2. The easiest and least expensive way to get a large T1 is to re-wind an old microwave transformer. These transformers are rated at about 1KW and are perfect. Go to a local TV repair shop and dig through the dumpster until you get the largest microwave you can find. The bigger the microwave the bigger transformer. Remove the transformer, being careful not to touch the large high voltage capacitor that might still be charged. If you want, you can test the transformer, but they are usually still good. Now, remove the old 2000 V secondary, being careful not to damage the primary. Leave the primary in tact. Now, wind on 12 turns of wire, twist a loop (center tap), and wind on 12 more turns. The guage of the wire will depend on how much current you plan to have the transformer supply. Enamel covered magnet wire works great for this. Now secure the windings with tape. Thats all there is to it. Remember to use high current transistors for Q1 and Q2. The 2N3055’s in the parts list can only handle 15 amps each.

3. Remember, when operating at high wattages, this circuit draws huge amounts of current. Don’t let your battery go dead :-).

4. Since this basic inverter project produces 120 VAC, you must include a fuse and build the project in a case.

5. You must use tantalum capacitors for C1 and C2. Regular electrolytics will overheat and explode. And yes, 68uF is the correct value. There are no substitutions.

6. This circuit can be tricky to get going. Differences in transformers, transistors, parts substitutions or anything else not on this page may cause it to not function.

This is low cost fully transistorised power inverter 60W circuit capable of driving medium loads of the order of 40 to 60 watts using battery of 12V, 15 Ah or higher capacity.

Transistors T1 and T2 (BC548) form a 50Hz multivibrator. For obtaining correct frequency, the values of resistors R3 and R4 may have to be changed after testing. The complementary outputs from collectors of transistors T1 and T2 are given to PNP darlington driver stages formed by transistor pairs T3-T4 and T6-T7 (utilising transistors BD140 and 2N6107). The outputs from the drivers are fed to transistors T5 and T8 (2N3055) connected for push-pull operation.

A 230V AC primary to 12V-0-12V, 4.5A secondary transformer (X1) is used. The centre-tapped terminal of the secondary of the transformer is connected to the battery (12V, 7Ah), while the other two terminals of the secondary are connected to the collectors of power transistors T7 and T8, respectively. When you power the circuit using switch S1, transformer X1 produces 230V AC at its primary terminal. This voltage can be used to heat your small electronic devices such as lamp, soldering iron, battery charger etc.

Somewhat higher wattage can be achieved by increasing the drive to 2N3055 transistors (by lowering the value of resistors R7 and R8 while increasing their wattage). Suitable heatsinks may be used for the output stage transistors. Transformer X1 is a 230V primary to 9V-0-9V, 10A secondary used in reverse.

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Inverter Circuit for Soldering Iron

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This inverter 12V DC to 240V DC can be used to power electric razors, stroboscopes and flash tubes, and small fluorescent lamps from a 12 volt car battery. In contrast to the usual feedback oscillator type of inverter, the oscillator of this inverter is separate from the output stage, which allows easy adjustment of the oscillator frequency to suit different applications.

The oscillator circuit consists of a 555 timer connected as an astable multivibrator. The inclusion of D1 ensures that the duty-cycle of the squarewave output is maintained at about 50%. The output of the 555 drives the base of T1 which switches current through one half of the primary of the transformer. T2 is driven from the collector of Tl and thus switches current through the other half of the transformer winding on opposite half cycles of the drive waveform. Zener diodes D4 and D5 protect Tl and T2 from any high-voltage spikes generated by the transformer.

The voltage applied to the transformer primary is stepped up and the required high output voltage appears across the secondary winding. Depending on the application the secondary voltage may or may not be rectified.

Download the full explanation about this inverter 12V DC to 240V DC circuit:

Inverter 12VDC to 240VDC Project

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