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3 Channel Analog Video Splitter with Video Amplifier
- Rajkumar Sharma
- 2.904 Views
- easy
- Tested
- SKU: EL105975
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If you need to drive multiple video gadgets or monitors from a single video signal source then this board is the right choice for you. This is a 3-channel video splitter with an amplifier and the circuit is built using discrete components. Q2 and Q1 act as a signal amplifier, Q3 act as output driver, trimmer potentiometer PR1 is provided to adjust the input signal swing, PR2 Trimmer is provided to set the gain of the amplifier, D1 is the power LED. The operating power supply is 12V DC and it draws 100mA current. RCA Connector J4 is the Video signal input, RCA Connector J1, J2, J3 provide the outputs. The default gain of the circuit is 4. The bandwidth is 5Mhz, input and outputs impendence are 75 Ohms. It is important to use all 3 channels at a time or change R11 to 150 Ohms if you will only use 1 x channel or 82 Ohms if 2 x channels are in use. Adjusting the board is very easy, just connect a voltmeter at the base of Q2 and adjust the PR1 so the voltage at the base of Q2 is 1V.
Features
- Power Supply 12V Vdc
- Current Consumption 100mA
- RCA Connector for Video Input
- 3 x RCA Connectors for Video Output
- Trimmer Potentiometer for Gain Adjust
- Trimmer For input signal Swing Adjust
- On-board Power LED
- PCB Dimensions 48.74 x 43.66mm
Schematic
Parts List
| No. | Qnty. | Ref | Desc. | Manufacturer | Supplier | Supplier Part No |
|---|---|---|---|---|---|---|
| 1 | 1 | CN1 | 4 PIN MALE HEADER 2.54MM PITCH | DIGIKEY | S1011EC-40-ND | |
| 2 | 3 | C4,C5,C7 | 100uF/25V ELECTROLYTIC CAPACITOR | NICHICON | DIGIKEY | 399-6650-1-ND |
| 3 | 2 | C2,C8 | 0.1uF/50V SMD SIZE 0805 | YAGEO | YAGEO | |
| 4 | 2 | C3,C6 | 10uF/50V ELECTROLYTIC | NICHICON | DIGIKEY | 493-5915-1-ND |
| 5 | 1 | C1 | 100uF/16V SMD SIZE 1210 | TAIYO YUDEN | DIGIKEY | 587-5426-1-ND |
| 6 | 1 | D1 | LED RED COLOR SMD SIZE 0805 | OSRAM | DIGIKEY | 475-1415-1-ND |
| 7 | 1 | D2 | 1N4148 SMD DIODE | MICROCHIP | DIGIKEY | 1N4148UR-1-ND |
| 8 | 1 | J1 | RCA JACK | KYCON INC | DIGIKEY | 2092-KLPX-0848A-2-R-ND |
| 9 | 1 | J2 | RCA JACK | KYCON INC | DIGIKEY | 2092-KLPX-0848A-2-R-ND |
| 10 | 1 | J3 | RCA JACK | KYCON INC | DIGIKEY | 2092-KLPX-0848A-2-R-ND |
| 11 | 1 | J4 | RCA JACK | KYCON INC | DIGIKEY | 2092-KLPX-0848A-2-R-ND |
| 12 | 2 | PR1,PR2 | 2.2K TRIMMER POTENTIOMETER | BOURNS | DIGIKEY | 3362P-1-222LF-ND |
| 13 | 1 | Q1 | BC857 SMD SOT23-3 | NEXPERIA | DIGIKEY | 1727-2924-1-ND |
| 14 | 1 | Q2 | BC847 SMD SOT23-3 | NEXPERIA | DIGIKEY | BC857BLT3GOSCT-ND |
| 15 | 1 | Q3 | BD139 | ST | DIGIKEY | 497-12137-ND |
| 16 | 1 | R1 | 8.2K 5% SMD SIZE 0805 | YAGEO | MOUSER | |
| 17 | 2 | R2,R3 | 1K 5% SMD 0805 | YAGEO | MOUSER | |
| 18 | 1 | R4 | 10K 5% SMD SIZE 0805 | YAGEO | MOUSER | |
| 19 | 1 | R5 | 3.3K 5% SMD SIZE 0805 | YAGEO | MOUSER | |
| 20 | 4 | R6,R7,R8,R12 | 75E 1% SMD SIZE 0805 | YAGEO | MOUSER | |
| 21 | 2 | R9,R13 | 180E 5% SMD SIZE 0805 | YAGEO | MOUSER | |
| 22 | 1 | R10 | 470E 5% SMD SIZE 0805 | YAGEO | MOUSER | |
| 23 | 1 | R11 | 56E 5% SMD SIZE 0805 | YAGEO | MOUSER |
Connections
Gerber View
Photos
Video
BD139 Datasheet
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Can you tell me can I use the same circuit to get 4 outputs from a single input or the whole circuit will change if so then can you please provide a solution for it.
Check this project -> https://www.electronics-lab.com/project/4-channel-analog-video-distribution-amplifier/
Thank you for this.
Can PAL format video signals also be distributed using this circuit?
If the PAL signal bandwidth is 5MHz, then this board will be able to amplify. I suppose yes.
I was also looking for a 4 channel output variant, but AD8010 seems to be a bit old and hard to find for newer designs. Shouldn’t this transistors circuit work for 4 outputs if R11 value is reduced to ~39 Ohms, or will that be too much for Q3 to handle?
Another question: should the DC blocking capacitors be really that big? I would assume something around 100 nF would be enough, unless I’m missing something else in terms of signal distortion.
I also wonder if this can work from 5v or 3.3v by adjusting some of the resistor values…
Thanks!
You may check this board for 4 outputs: https://www.electronics-lab.com/project/4-channel-analog-video-distribution-amplifier/ . This board uses AD8010 high-speed opamp and the circuit provides 46dB of output-to-output isolation at 5Mhz.