Showing posts with label 220. Show all posts
Showing posts with label 220. Show all posts
Wednesday, October 15, 2014
Simple DPA 220 schematic
T1 to T6 create the input differential stage. The D7 and D8 zener diodes stabilize at 5V. These are just the simplest low-power zeners, only they have to be coupled in tolerance of 200 milivolts, which should not be a problem. T1 to T6 are common all-purpose low-power transistors with high Hfe. These six and maybe the next four have to be coupled in tolerance of 25%.
The T7 and T8 are fast, switching application types.
T9 and T10 have to be fast and must hold a high voltage, thus the best are the "video" types - BF469/470. T15 and T16 are the same types.
The C9, C10 and C15 should stand voltages higher than usual 50 V - I dont know why.
D3 to D6 can be any silicon type, not Scottky, the ones listed below are just all-purpose low-current ones for 150 V. These diodes should be rather fast - "switching types".
The T11 and T12 stabilize the BIAS current for the power stage. T11 also serves as a temperature sensor, and is mounted to the cooler of power transistors.
T13 and T14 secure the output current - in cooperation with R38 and R39.
The output transistors used here are Tesla types - Tesla is a former local devices manufacturer - the pair in each branch can be replaced with a single power darlington, like BD649/BD650. They should have Pc > 150W, Ic > 15A, Uceo > 100V.
In this case obviously the R38+R40 / R39+R41 must be connected parallel. These resistors should be able to absorb high power - at least 2 W, but Id use 5W ones.
The output filter improves stability of the amp when working with complex impedance of speakers - it is quite important. The resistors are high-power ones again, the coil is 13 turns of a 1.2 mm wire on a 8 mm thorn (diameter). R43 is placed coaxially in the coil.
The schematic also includes power supply capacitors and rectifier - the capacitors size is not crucial, generally the bigger the better. The rectifier originally consists of four silicon 10A diodes, but you can use whatever you have - rectifier bridge etc. The trafo should be a 2 * 30 V / 7 A type so that you have +/- 40 V on the power supply capacitors.
In the scheme theres also a thermistor that is supposed to be connected to some additional circuits that secure temperature and other things. The complementary input stage of DPA amps is an unmistakable heir of earlier designs published by Mr. Borbely in several issues of Volume 1984 of the Audio Amateur.
The T7 and T8 are fast, switching application types.
T9 and T10 have to be fast and must hold a high voltage, thus the best are the "video" types - BF469/470. T15 and T16 are the same types.
The C9, C10 and C15 should stand voltages higher than usual 50 V - I dont know why.
D3 to D6 can be any silicon type, not Scottky, the ones listed below are just all-purpose low-current ones for 150 V. These diodes should be rather fast - "switching types".
The T11 and T12 stabilize the BIAS current for the power stage. T11 also serves as a temperature sensor, and is mounted to the cooler of power transistors.
T13 and T14 secure the output current - in cooperation with R38 and R39.
The output transistors used here are Tesla types - Tesla is a former local devices manufacturer - the pair in each branch can be replaced with a single power darlington, like BD649/BD650. They should have Pc > 150W, Ic > 15A, Uceo > 100V.
In this case obviously the R38+R40 / R39+R41 must be connected parallel. These resistors should be able to absorb high power - at least 2 W, but Id use 5W ones.
The output filter improves stability of the amp when working with complex impedance of speakers - it is quite important. The resistors are high-power ones again, the coil is 13 turns of a 1.2 mm wire on a 8 mm thorn (diameter). R43 is placed coaxially in the coil.
The schematic also includes power supply capacitors and rectifier - the capacitors size is not crucial, generally the bigger the better. The rectifier originally consists of four silicon 10A diodes, but you can use whatever you have - rectifier bridge etc. The trafo should be a 2 * 30 V / 7 A type so that you have +/- 40 V on the power supply capacitors.
In the scheme theres also a thermistor that is supposed to be connected to some additional circuits that secure temperature and other things. The complementary input stage of DPA amps is an unmistakable heir of earlier designs published by Mr. Borbely in several issues of Volume 1984 of the Audio Amateur.
Wednesday, August 13, 2014
AC 220 Volts Flashing Lamps Circuit
This schema is intended as a reliable replacement to thermally-activated switches used for Christmas tree lamp-flashing. The device formed by Q1, Q2 and related resistors triggers the SCR. Timing is provided by R1, R2 & C1. To change flashing frequency do not modify R1 and R2 values: set C1 value from 100 to 2200µF instead. Best performances are obtained with C1= 470 or 1000µF and R4= 12K or 10K. Due to low consumption of normal 10 or 20 lamp series-loops intended for Christmas trees (60mA @ 230V typical for a 20 lamp series-loop), very small and cheap SCR devices can be used, e.g. C106D1 (400V 3.2A) or TICP106D (400V 2A), this last and the suggested P0102D devices having TO92 cases.
Parts:
R1 = 100K
R2 = 1K
R3 = 470R
R4 = 12K
R5 = 1K
R6 = 470R
Q1 = BC327
Q2 = BC337
D1 = 1N4007
D2 = 1N4007
D3 = 1N4007
D4 = 1N4007
D5 = P0102D (SCR)
C1 = 1KµF-25V
PL1 = Male Mains plug
SK1 = Female Mains socket For proper operation
it is absolutely necessary to employ high Gate-sensitive SCRs. If you are unable to find these devices you can use Triacs instead. In this case the schema operates also with relatively powerful devices. A recommended Triac type is the ubiquitous TIC206M (600V 4A) but many others can work. Please note that, in spite of the Triac, diode bridge D1-D4 is in any case necessary.
Warning! The device is connected to 230Vac mains, then some parts in the schema board are subjected to lethal potential! Avoid touching the schema when plugged and enclose it in a plastic box.
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