How to change the polarity of the output voltage of a high voltage power supply

DC boost is to provide the lower DC voltage provided by the battery, to the required voltage value, its basic working process is: high-frequency oscillation to produce a low-voltage pulse - pulse transformer step-up to a predetermined voltage value - pulse rectification to obtain high-voltage direct current, so the DC boost circuit belongs to a type of DC DC circuit.

In the battery-powered portable devices, the high voltage required in the circuit is obtained through the DC boost circuit, these devices include: mobile phones, pagers and other wireless communication equipment, flashes in cameras, portable display devices, electric shock devices such as electric mosquito swatters, etc.

1. Several simple DC boost circuits.

The following are several simple DC boost circuits, the main advantages: simple circuit, low cost; Disadvantages: low conversion efficiency, low battery voltage utilization, low output power. These circuits are suitable for use in multimeters as an alternative to high-voltage tandem batteries.

2. 24V power supply CRT high voltage power supply.

Some camera CRTs use an 11 4 cm (4 5 in) pure planar CRT as the display component, with an anode voltage of 20 kV, a focusing pole voltage of 3 2 kV, an accelerating pole voltage of 1000 V, and a high-voltage component powered by 24 V DC. The following circuits are designed to replace and repair the high-voltage components of these displays (the circuit is selected from an online article, the original author is unknown). The design of this circuit can also provide a reference for other step-up circuit designs.

Basic principle: NE555 constitutes a pulse generator, the potentiometer VR2 can be adjusted to produce a pulse with a frequency of about 20kHz, and the potentiometer VR1 adjusts the pulse width. TR1 is the push stage, and the pulse transformer T1 adopts reverse polarity excitation, that is, TR2 cuts off when TR1 is on, TR2 is turned on when TR1 is turned on, and D3, C9, VR3, R7 and D4, R6, TR3 form a high-voltage protection circuit.

VR2 is used to adjust the frequency, and VR2 can adjust the high voltage size.

The VR2 is made with a precision adjustable resistor. T2 can be used as a color TV output transformer. The author chooses the line output transformer of Toyo SE 1438G series 35cm (14 inches) color TV, using this transformer anode voltage up to 20kV, and then appropriately select the resistance value of R8 to make the accelerating pole voltage 1000V, and the resistance value of R9 to make the focusing pole voltage 3 2kV.

The entire assembly is encapsulated in an aluminum box with the aluminum case grounded, which reduces interference to the circuit.

It should be possible to convert it with a converter.

It's useful, many of your classmates are using the Eagle King anti-power rationing socket. In fact, the meter only limits the wattage of resistive electrical appliances that generate heat, while capacitive electrical appliances such as computers and desk lamps do not have a meter and have no wattage limit. The use of oversized electrical appliances heats up quickly, hair dryers, electric kettles == will trip, burst electricity, at present, many college students are distressed by this life problem, worrying.

If you want to use high-power electrical appliances without tripping, look for the old brand, and the Eagle King limited socket should be able to help you. Safe and easy to use. Many university dormitories are said to be using well, and many university dormitories are currently being successfully used.

It is recommended to buy another voltage regulator to use together, at least there will be no fire.

It should be useful, otherwise what are you doing with it, we also have something to buy in our dormitory.

1. The opening sequence of the power supply is: first open the AC switch (the boat-shaped switch in the experimental box), then open the DC switch, and finally open the control switch of each module. The power is turned off in the opposite order.

2. Do not connect the line with electricity in the experiment, the correct way is to connect the line after the power is off, and carry out the experiment. 3. All the chips on the main circuit board of the experimental box have been strictly inspected when leaving the factory, so do not insert and unplug the chips at will when doing experiments. 4. The use of the stacked connecting wires in the experimental box is as follows:

When the wire is inserted, it should be vertical, do not use force, pinch the end of the wire close to the jack with your hand when pulling it out, and then rotate it left and right a few times, the wire will naturally be loosened from the jack, pop out, and do not pull the wire upwards hard, which is easy to cause damage to the wire and the jack. 5. During the experiment, it should be operated in strict accordance with the teacher's requirements and experimental instructions, and do not randomly move switches, chips and other components to avoid damage to the experimental box. Diodes and digital tubes in the component library must be subject to polarity.

6. If there is an abnormal situation due to improper operation or other reasons in the experiment, such as the digital tube display is unstable, flickering, the chip is hot, etc., first cut off the power immediately, and then report to the teacher, do not ignore the phenomenon, continue the experiment, so as not to cause serious consequences.

Staying up all night is very simple, and it can be easily solved in the dormitory:

1.Stealing electricity, but it seems to be a bit serious after that.

2.There should be an activity room on every floor, as long as you know the classmate who took the key, it's a matter of one sentence. The atrium of the 6th house is open before the exam, everyone can go in for self-study, there are many tables and chairs, the environment is okay, and the other dormitory buildings do not know.

If you really can't go out and rent a house, this is the case if your classmates are prepared for gre.

The telecommunications academy innovation base in the complex can stay overnight, but you have to know the people inside. The research and education building also provides electricity overnight, but now that it is strictly controlled, it is difficult to stay in it all night. In fact, the entire complex is powered overnight, and as long as you can stay inside, you can stay overnight.

You can ask the seniors in the school's post bar, and if you are in that school yourself, you can also try it yourself.

If there is no electricity, the power will be cut off at 22:47 every day, and only the living lamp will have electricity.