Showing posts with label Circuits. Show all posts
Showing posts with label Circuits. Show all posts
Tuesday, November 18, 2014
Video Amplifier Circuits
Video amplifier circuit is simple and can be used. Video amplifier circuit was constructed from 2 pieces of transistors BC550 and BC560. The source voltage used for supplying the video amplifier circuit is 5VDC. Video amplifier circuit is equipped with a powerful regulator which flows through both transistors T1 and T2, the components used to manage these flows are P1 and P2. Then the video amplifier circuit is also equipped with limiting the maximum current that passes through T1 and T2. The components in black block functions as limiting the maximum current that is passed by the T1 and T2 for no more than 5mA.
Monday, October 27, 2014
X Ray Protector Circuits
A protector system that is applied at the beginning of the television technique, therefore most often found on old aircraft models. If the high voltage anode of the picture tube flyback tranfo exceed the permitted limit, the picture tube can generate x-rays from the anode and shadowmask are bombarded by electrons at high speed. To avoid this problem then mounted x-ray surge protector circuit , which automatically "horizontal section will be turned off" if the high voltage from the flyback over.
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| X-Ray vertical protect |
The workings of x-ray protector:
- High voltage flyback sampled (generally taken from the pin-heater), rectified and is derived using a divider (devider) that uses a resistor-type high-precision resistor. Sample voltage is used to determine whether the condition is normal flyback voltage or over.
- A "zener diode" as a voltage sensor connected to the sample. In normal conditions the amount of the sample voltage is below the zener voltage of diode so that the condition "off" or is not transparent.
- Suppose there is a sudden event increased flyback voltage - the voltage will rise above the sample diode voltage value, which causes the diode "on" or voltage through the diode, which would trigger protectionist active work.
Problems that can lead to x-ray active protector works:
- Damage that causes the power supply voltage B + or incorrect adjustment over
- Resonant capacitor to the collector of transistor HOT off the decline or solder
- Tranfo replacement flyback mounted do not match.
- Damage to one part in the sensor circuit protectors x-ray alone
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| X-ray Protect Circuit |
Friday, October 10, 2014
LM3909 Continuity tester circuit diagram circuits and explanation
A very simple continuity tester electronic project can be designed using the LM3909 LED flasher integrated circuit .
This continuity tester project , require few external electronic parts and can be used for testing continuity of coils and cables .
This continuity tester project must be powered from a 1.5 volt DC power supply , you can use a 1.5 volts battery cell .
Thursday, October 2, 2014
Simple Audio Mixer Circuits
The amplifiers of a LM3900N device can be conveniently used to make a mixer unit for audio purposes; the unit enables three separate audio signals to be mixed together to produce a composite output.
The audio mixer circuit shown provides this facility using only a single LM39OON device and also enables any one channel to be selected by switches. The currents passing through the resistors R4, R8 and R,, are summed in the input circuit of the fourth amplifier. lf S; is open, amplifier 1 will be driven to saturation by the current passing through R2. lt will therefore be inactive.
Th below shown simple mixer circuit will work with two or three channels, providing excellent input isolation and exceptional frequency response, extending well over the top end of the audio spectrum. lt is usable by one or more instruments plus microphone, or with special effects, such as mixing en input with pink noise, to give surf’. The unit will give 8db gain, and since low-level signals are involved, should be housed in an aluminum box. lf a mains supply is used, the usual anti-hum precautions must be taken. lt is useful to use scaled slider potentiometers, so that effects may be recreated.
The audio mixer circuit shown provides this facility using only a single LM39OON device and also enables any one channel to be selected by switches. The currents passing through the resistors R4, R8 and R,, are summed in the input circuit of the fourth amplifier. lf S; is open, amplifier 1 will be driven to saturation by the current passing through R2. lt will therefore be inactive.
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