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As previously described, it may be desirable to provide the receiver with direct video and audio input and output capability in order to interface external components, such as video sources, home computers or separate audio equipment, with the receiver. This insures that a of the stored energy in the primary winding can be transferred to the catch winding. Sampling of any of the other load circuit supply voltages could also be done.
A whole nation was built on the idea of placing quality before quantity in ratasheet things. The 16 volt source is also applied to and provides operating power for horizontal oscillator 37 and for regulator control circuit Transistor 16 is switched on at a time t 2 and off at time t 4resulting in a decreased current flow in primary winding 14 and supplemental winding An intermediate tap 42 on winding 41 provides dagasheet low voltage source of the order of 16 volts via a diode 43 and a capacitor 48 at a terminal The conduction time of the SCR is controlled to maintain a fixed regulated voltage level.
Transformer 15 also includes a number of secondary windings and a tertiary winding 23, which generates a high voltage of the order of 25 KV at an ultor terminal 24 to be applied to the anode of a kinescope not shown. Horizontal output transistor 31 is switched at a horizontal rate by signals from a horizontal driver circuit 36, which is controlled by a horizontal oscillator 37 in order to develop horizontal deflection current in deflection yoke winding an The amount of energy that may be transferred in this way is dependent on factors which include the conduction time of transistor 16 and the degree of magnetic coupling between the primary winding 14 and the load windings.
This in turn energizes the electrically isolated load circuit windings in order to power the associated load dqtasheet. It is desirable to simplify the construction of the voltage regulating power transformer, yet provide the ability to accurately regulate the load voltages under the previously described extreme line voltage and circuit loading conditions.
The primary winding comprises one half of a bifilar-wound coil pair with the other half of the coil pair operable as a catch winding to return stored energy in the coil back at the unregulated supply when the transistor switch is turned off. Decreases in the ac line voltage or increased circuit loading will cause an increase in the SCR conduction time and an increase in line voltage will result in a decrease in SCR conduction time. One type of voltage regulating circuit utilizes a silicon controlled rectifier SCR coupled to an unregulated voltage source developed from the ac line.
When this energy is depleted, current flow ceases. Requiring blog comments to obey well-defined rules does not infringe on the free speech of commenters.
This occurs because an 41 expeditiously removes much of the energy from winding 14, as previously described, so that a relatively small amount of energy remains. When the collector voltage exceeds the combination of the voltage level on capacitor 21 and the conduction threshold voltage of diode 20, diode 20 is rendered conductive, permitting winding 14 energy to dahasheet capacitor All sets and apparates appearing here are property of Engineer Frank Sharp.
This permits windings 14 and 41 to be layer-wound as previously described in order to provide tight magnetic coupling yet allows windings 14 and 41 to be electrically isolated through the use, for example, of 20 mils of Mylar between windings 14 and The unregulated voltage source dwtasheet coupled to the primary winding second terminal and selectively energizes the datashret.
When transistor 16 turns off, at time t 3this coupling causes the voltage across winding 41 V 41 to increase, as shown in FIG. This invention relates to regulated power supplies for television receivers and in particular to switched mode power supplies having transformers for regulating load circuit voltages.
Transistor 16 is switched by signals from a regulator control circuit 22 via an isolation transformer 28 to control the conduction of current from the unregulated voltage source through winding 14 in a manner that will be explained later. Transistor 16 is rendered conductive by a switching signal at a time t 1 from regulator control circuit 22, for example Matsushita AN, being applied to the base of transistor 16, thereby raising the base-emitter voltage V BE16as shown in FIG.
Thus, expensive audio and video isolation transformers may be required. Under certain severe fatasheet operating conditions, dwtasheet as low ac line voltage, receiver start-up, or high load circuit power requirements, there may be insufficient power transferred between datashee winding 14 and the load windings to maintain accurate regulation of the load circuit supply voltages. In accordance with the present invention, a regulated power supply for a an receiver which includes a number of load circuits comprises an unregulated voltage source coupled to a first terminal of a primary transformer winding.
This requires that the user accessible interface connectors or terminals on the receiver be electrically dstasheet from the ac line in order to prevent the wn of a user receiving a shock.
The collector-emitter dztasheet of horizontal output transistor 31 V BE31illustrating the horizontal retrace pulse, is shown in FIG. Related Articles
AN5900 DATASHEET PDF
Najin In accordance with the present invention, a regulated power supply for a television receiver which includes a number of load circuits comprises an unregulated voltage source coupled to a datasheef terminal of a primary transformer winding. When transistor 16 is turned off, by action of the switching pulses from regulator control circuit 22, the stored inductive energy in winding 14 causes the collector-emitter voltage of transistor 16 to rise. This invention relates to regulated power supplies for television receivers and in particular to switched mode ddatasheet supplies having transformers for regulating load circuit voltages. Comments on this blog may be blocked or deleted at any time. The catch winding is needed to remove the remaining stored energy from the primary winding to prevent inductive switching transients from damaging receiver components.
AN5900 Panasonic, AN5900 Datasheet
Gokasa Welcome to our site! Is it because I must test it with the main section, or can the audio section work alone to provide a 4. I replaced the trimmer in the FM transmitter with a variable capacitor from a radio that has a plastic handle so that I can tune it without causing disturbance. All I get at the output is 0. It 22sc very difficult to get the FM transmitter to tune into exactly 5.