CCTV, Security


Frequently Asked Questions

Equipment for the systems of video surveillance in Kiev
> ⇒Power supplies

Блоки питанияPower supply unit (PSU) is a device thatdesigned to generatevoltage needed by the system,voltage of an electricnetwork. Most power supplies convert AC voltage mains frequency 50 Hz to 220 (for Ukraine and CIS countries other countries use different levels and frequencies) at a predetermined constant voltage.
Distinguish between transformer and switching power supplies.
Classic power supplyis the transformer PSU.Generally, it consists ofstep-down transformer,the primary windingdesigned for mains voltage.Then set hair straightener,converts AC voltagein the constant. In mostrectifier consists offrom a single diode (odnopoluperiodnyjEliminator) or four diodes,forming a diode bridge (dvuhpoluperiodnyjrectifier). Sometimes usedother schemes, such as in rectifierswith a doubling of voltage. Afterthe rectifier is installedfilter smoothing fluctuations.Usually it is simply a large-capacity capacitor. Also in the schema can be mounted high-frequency interference filters, wavelet, protection against SHORT-CIRCUITS, voltage and current regulators.
In pulse power suppliesAC input voltagefirst is straightened. The ReceivedDC voltage is usedto power the generator, usingwhich it is convertedthe rectangular pulses with a frequencyfrom 10 kHz to 1 megahertz,served on the transformer.The PSU can applysmall-sized transformers— This is so that theincreasing the frequency of the supply voltagereduced requirements for dimensions(cross section) of the core. In mostcases, the core canbe made of ferromagneticmaterials, unlike coreslow-frequency transformers,that use steel. Oneoutput transformeris used to control thegenerator. Depending on thevoltage on it (for example,at change of load current) changes the frequency or duty cycle at the generator output. Thus, using this feedback power supply supports a stable output voltage.

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