VM-AI1i Assembly step by step
This page show how to correctly assembly the VM-AI1i kit (elaboration unit), step by step.
Figure 1 shown the two PCBs that are the mechanical support of VM-AI1i. As you can see, are two-layer PCBs, with double side ground plane and star ground (elaboration unit). A state-of-art PCBs, obviously Made in Italy!
The kit parts
Figure 2 shown the parts that compose the VM-AI1i kit. All components are first class, only the best of the best: metal-film 1% resistor from Vishay, audio grade and low-esr electrolytic capacitors from Nichicon and Kemet, film capacitors from Wima and Panasonic, Op-Amp from Texas Instruments, MCU from Microchip, leds from Avago and Kingbrite, mechanical (header, sockets) parts from 3M etc etc…
Bill of Material
Below there is the bill of material of the elaboration unit of VM-AI1i kit.
|R1, R10 (2X)||50kΩ||1/4in Trimmer|
|R2, R11 (2X)||49.9 kΩ, ¼ W, ±1%||Yellow White White Red Brown|
|R3, R12, R19, R21 (4X)||6.65 kΩ, ¼ W, ±1%||Blue Blue Green Brown Brown|
|R4, R5, R6, R8, R13, R14, R15, R17 (8X)||20 kΩ, ¼ W, ±1%||Red Black Black Red Brown|
|R7, R16 (2X)||10 kΩ, ¼ W, ±1%||Brown Black Black Red Brown|
|R9, R18, R23 (3X)||100 kΩ, ¼ W, ±1%||Brown Black Black Orange Brown|
|R20, R22 (2X)||1 kΩ, ¼ W, ±1%||Brown Black Black Brown Brown|
|R24…R29 (6X)||2.2 kΩ, ¼ W, ±1%||Red Red Black Brown Brown|
|C1, C4 (2X)||1uF, 50V||Electrolytic, Audio Grade|
|C2, C5 (2X)||120pF||Ceramic|
|C3, C6 (2X)||1uF, 50V||Polyester film|
|C7 (1X)||470uF, 25V||Electrolytic|
|C8, C9, C11, C13, C15, C16, C19 (7X)||100nF, 63V||Polyester film|
|C10 (1X)||10uF, 25V||Electrolytic|
|C12, C14 (2X)||100uF, 25V||Low-ESR Electrolytic|
|C17, C18 (2X)||220nF, 63V||Polyester film|
|D1…D8 (8X)||1N4148||Switching diode|
|D9 (1X)||SB140||Schottky barrel diode|
|T1…T6 (6X)||BC337||NPN g.p. transistor|
|IC1 (1X)||TC1044S||Charge pump|
|IC2 (1X)||TL072||Dual low-noise operational amplifier|
|IC3 (1X)||LM7805||5V Voltage regulator|
|IC4 (1X)||TL074||Quad low-noise operational amplifier|
|IC5 (1X)||–||VM-AI1i v3.5/2013 Preprogrammed MCU|
|JP1E (1X)||8 Pin Male header|
|JP2E, JP3E (2X)||3 Pin Male header|
|JP4E (1X)||6 Pin Male header|
|S1, S2 (2X)||N.O. Tactile buttons|
|2X 8Pin 2.54mm/0.1in IC socket|
|1X 14Pin2.54mm/0.1in IC socket|
|1X 20Pin 2.54mm/0.1in IC socket|
|JP1D (1X)*||8 Pin Female header|
|JP2D, JP3D (2X)||3 Pin Female header|
|JP4D (1X)||6 Pin Female header|
* In italics there are the display units mechanical parts.
Ok, let’s go to start!
Bend the resistors (ALL resistor; the picture show how done this step using a bending tool).
Separates the diodes.
Bend the diodes.
Solder the eight 1N4148 (D1…D8) diodes. Notes the direction Anode-Cathode (the side with the black band painted).
Solder the six 2.2k (R24…R29) resistors.
Solder the two 49.9k (R2, R11) resistors.
Solder the eight 20k (R4…R6, R8, R13…R15, R17) resistors.
Solder the three 100k (R9, R18, R23) resistors.
Solder the four 6.65k (R3, R12, R19, R21) resistor.
Solder the two 1k (R20, R22) resistor.
Solder the two 10k (R7, R16) resistor.
Solder the SB140A (D9) Schottky diode.
Solder the two 50k (R1, R10) trimmers, the two 120pF (C2, C5) ceramic capacitors and the seven 100nF (C8, C9, C11, C13, C15, C16, C19) film capacitors.
Solder the two 220nF (C17, C18) film capacitors and the four sockets (two 8P, one 14P and one 20P), looking carefully the references.
Solder the two buttons (S1, S2).
Using a nail, bend the pins of uA7805 regulator…
…in this way!
Solder the uA7805 (IC3) voltage regulator.
Look carefully this capacitors: there are two 1uF/50V capacitors and only one 10uF/50V.
Solder the 10uF/50V (C10) capacitor.
Solder the two 100uF/25V (C12, C14) Low-esr capacitors and the two 1uF/50V (C3, C6) film capacitors.
Solder the two 1uF/50V (C1, C4) audio grade capacitors.
Solder the 470uF/25V (C7) filter capacitor.
Join the headers with the sockets.
Finally, solder the headers. After, using a flux cleaner, we can remove the excess flux.
Ok, now we can measure the voltages (I’ve used a 12Vdc power supply source). Point #1 – Cathode of D9, expected value: 11.8V.
Voltage measuring. Point #2 – out of IC3, expected value: 5V.
The linear ICs. There are one charge pump (IC4, TC1044SCPA) voltage converter, one dual-low-noise (IC1, TL072) operational amplifiers and one quad-low-noise (IC2, TL074) operational amplifiers.
Insert the charge pump IC (IC4, TC1044SCPA) . Look carefully the reference (pin #1).
Voltage measuring. Point #3 – pin #4 of IC1, expected value: -11.8V.
Voltage measuring. Point #4 – pin #11 of IC2, expected value: -11.8V.
Voltage measuring. Point #5 – pin #1 of IC4, expected value: 5V.
Voltage measuring. Point #6 – pin #8 of IC1, expected value: 11.8V.
Voltage measuring. Point #7 – pin #4 of IC2, expected value: 11.8V.
Ok, after correctly inserting the linear integrated circuits and the preprogrammed MCU, the heart of VM-AI1i, we are ready to the final test (I’ve used the old display).
…and that’s it! Enjoy!