|
Description:
Tr1 and Tr2 transistors functions as direct
coupled voltage amplifiers. R6 resistor, D1 and D2 diodes determine the
standby current of complement driver stage (Tr3/Tr4) and output stage
(Tr5/Tr6). C3, C5, C6 and R3 help keeping stability. Amplifier's input
sensitivity is 400mA at 4 ohm load and 12V supply and 600mV at 8 ohm
load and 17V supply.
Gain can be increased by decreasing R4 value but it is not recommended because of increasing distortion.
Notes:
Speaker's ground must be connected directly to the ground of supply stage and must be kept away from the circuit.
Separate supply connections must be applied to the supply connection points.
|
|
Description:
While detecting discontinuities on a circuit board, it is
probable to include resistors, semiconductors or other elements in
measurements. This situation may cause wrong results. On the other hand
sometimes the voltage or current of the multimeter may defect some
circuit components.
Our circuit overcomes this inconvenient
conditions. The circuit determines greater than 1 ohm values as
discontinuity. Measure voltage is not more than 2mV. So no kind of
diode, IC or other component is bypassed. Maximum current output of
the circuit is about 200uA.
Indicator of the circuit is a LED. Voltage supply may be two 9 Volt batteries.
Voltage
adjustment of the amplifier is done by P1 potentiometer. To do this
process, first short circuit the probes and then turn P1 until LED
brights. When you separate the probes again LED will fade out.
This is a cheap and very useful circuit. You can build it on a PCB to use more easily.
|
|
Description:
This voltage controlled switch circuit operates when a voltage level which is previously
adjusted is applied to the input. Circuit is designed for 24V supply
but can be used in a range of 18V-36V. Voltage level which triggers the
circuit can be adjusted by P1 potentiometer. A stabilized voltage is
applied to this potentiometer through zener diode and Tr5. When the
input voltage level exceeds this value TR1 starts conducting and
afterwards Tr2, Tr3, Tr4 transistors conduct and relay switches on.
Switch S1 that is connected to relay, carries the signal from Tr3 to Tr1 through R1 and keeps Tr1 conducting.
When the input is short circuited, D1 diode keeps the circuit operating and you can omit it if you want.
|
|
<< Start < Prev 1 2 3 4 5 6 7 8 9 10 Next > End >>
|
| Results 19 - 21 of 36 |
