Total solder points: 82 Difficulty level: beginner 1 2 3 4 5 advanced Dc to Pulse Width Modulator K8004 C ient control of D Allows very effic or lights.
Features & Specifications Features: PWM range: 0 to 100%. PWM frequency: 100 to 5000Hz adjustable. Minimum PWM offset: 0 to 20% adjustable. Adjustable sensitivity: 2.5 to 35VDC Short circuit protection. Overload protection: 6.
Assembly hints 1. Assembly (Skipping this can lead to troubles ! ) Ok, so we have your attention. These hints will help you to make this project successful. Read them carefully. 1.1 Make sure you have the right tools: • A good quality soldering iron (25-40W) with a small tip. • Wipe it often on a wet sponge or cloth, to keep it clean; then apply solder to the tip, to give it a wet look. This is called ‘thinning’and will protect the tip, and enables you to make good connections.
Assembly hints 1.
Construction 1. Diodes. Watch the polarity ! 3. IC socket. Watch the position of the notch! 5. PCB pins D... CATHODE D1 : 1N4148 D2 : 1N4148 D3 : 1N4007 2. Resistors IC1 : 16P Vref 4. Trim potentiometer 6. Ceramic Capacitors R... C... RV...
Construction 7. Transistor 10. Screw connectors T1 : BC547 12. Transistor J1 : 2p 10mm M3 BOLT LOCK WASHER 8. Electrolytic capacitor. Watch the polarity ! C5 : 10µ F C6 : 10µ F C7 : 100µ F (40Vmin) J2 : 2p J3 : 2p M3 NUT T2 : BUK9535-55 or eq. C... 11. 5W Resistors R... 13. IC, Check the position of the notch ! R8 : 0,22 (R22) 2mm 9. Diode, check the polarity D4 : 6A2 / 6A6 CATHODE 6 D... IC1: SG3525 R9 : 0,22 (R22) R10 : 0,22 (R22) R...
Test 14. Test Connect the supplied 4k7 resistor between the + and - points of the load. Connect the Vref point to the DC input. Set preset RV3 to the middle of its adjustment range. Connect a DC voltage between 8 and 35V with the points +V and GND. Measure between the + and - points of LOAD with a voltmeter (set to read DC voltage). If everything goes well then the voltage on the output can be adjusted with RV2. Fig 1.
Different configurations 15. Different configurations K8004 Figure A : DC LOAD + LOAD Standard configuration, use a separate control voltage. - POWER SUPPLY (8...35VDC) - - GND GND + + +V DCIN - + DC CONTROL VOLTAGE (max. 35V) Figure B : K8004 + Connection to one of the analogue outputs of the K8000 interface card. If DAC1 is used then the circuit can be controlled with the demo program, "dimmer". The circuit can also be tested with the test program of the K8000.
Setting up 16. Setting up RV1: setting the minimum output voltage. Set the control voltage to zero (perhaps by disconnecting it). An initial pre-voltage can then be adjusted using preset RV1. This is especially useful with motors (in order to overcome mechanical resistance) and with halogen lamps (in order to pre-heat the filament). RV2: setting the maximum output voltage. Set the control voltage to the maximum voltage that you are going to use.
PCB 17.
Schematic diagram 18. Schematic diagram.
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