Rangkaian Pre-Amp mic condenser

Microphone amplifier circuit is simple, consisting of 2 levels. with wide dynamic regions, small noise, and can with a long cable about 50 meters.

Skema rangkaian Pre-Amp mic condenser

Note:

all capacitor (elco) using 25-voltto avoid the buzzing sound, use a good regulator supplayThis circuit can provide voltage 6-20volt

This circuit uses low noise transistors are type types: BC 650 C but the transistor is hard to find, so you can replace it with 109 BC is no less good. This condenser mic element in it is a very sensitive microphone, and to use this mic condenser required voltage between 2-10 volts, for that we can resistors in series with 1K-10 K ohms, in the picture above the tide 1k ohms

Pin BC109

1. Emitter
2. Base
3. ollector, connected to the case

BC109 limiting values

collector-base voltage 30 V
collector-emitter voltage 20 V
emitter-base voltage 5 V
collector current (DC) 100 mA
peak collector current 200 mA
peak base current 200 mA
total power dissipation Tamb £ 25 °C - 300 mW
storage temperature 65 +150 °C
junction temperature 175 °C
operating ambient temperature -65 +150 °C
DC current gain (hFE) IC = 10 mA; VCE = 5 V 100 -- 270

Microphone computer

The sound card for a PC generally has a microphone input, speaker output and sometimes line inputs and outputs. The mic input is designed for dynamic microphones only in impedance range of 200 to 600 ohms. Lazar has adapted the sound card to use a common electret microphone using this circuit. He has made a composite amplifier using two transistors.

Skema rangkaian microphone komputer

Transistor BC413B operates in common emitter to give a slight boost to the mic signal. This is followed by an emitter follower stage using transistor BC547C. This is necessary as the mic and circuit and battery will be some distance from the sound card, the low output impedance of the circuit and screened cable ensuring a clean signal with minimum noise pickup.

Transistor BC413

• Collector Emitter Voltage VCEO 30 V
• Collector Base Voltage VCBO 45 V
• Emitter Base Voltage VEBO 5.0 V
• Collector Current Continuous IC 100 mA
• Power Dissipation at Ta=25ºC PD 350 Mw Derate Above 25ºC 2.8 mW/ºC
• Power Dissipation at Tc=25ºC PD 1.0 W Derate Above 25ºC 8.0 mW/ºC
• Operating and Storage Junction TJ, Tstg ºC - 55 to +150

Transistor BC547C

• Collector-Base Voltage VCBO (IE = 0) 50 V
• Collector-Emitter Voltage VCEO (IB = 0) 45 V
• Emitter-Base Voltage VEBO (IC = 0) 6 V
• Collector Current IC 100 mA
• Collector Peak Current ICM 200 mA
• Total Dissipation at Ptot TC = 25 oC 500 mW
• Storage Temperature Tstg -65 to 150 oC
• Operating Junction Temperature Tj Max. 150 oC