Assembling advice

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The expected assembling time of the amplifier and controller together is approximately four hours. Most problems are caused by working too fast or too superficial. The parts should always be soldered according to their mounting height.

Parts with a low mounting height

Examples: SMD op-amps, diodes, resistors, ceramic capacitors, axial inductances, the crystal.

These parts should be assembled at first. It is very important that you solder them carefully, because it’s hard to do changes there after the other parts have been mounted.
  • Pin 1 of the ICs is marked by a dot at the housing. These pins are marked by a white dot at the boards.
  • To mount the SMD parts (IC2, IC4, IC6, IC68 and the GlobalTop PA6H GPS module), first solder only one of the four corner pins. Then unsolder and solder this pin repeatedly until the component is properly placed. After that solder the other pins. It is not necessary to use solder paste.
  • The cathode (-) of the diodes is marked by a black or white ring at the housing. These sides are marked white on the boards. (Note the reverse markings on the LEDs. The anode is the longer wire of the LED which is marked at the board by a white square.)
  • The values of the resistors should be verified by a multimeter, because it is sometimes difficult to distinguish between certain colors, as for example, between red and brown.

Figure 48: Electrical components of the starter kit

Parts with a medium mounting height

Examples: Sockets, mini USB jacks, LEDs, push-button, potentiometer, resistor networks, the GPS module, transistors, the voltage transformer, mount sockets for the display

  • The anode (+) of a LED has a longer wire than the cathode (-). The hole for the anode is marked by white squares on the board.
  • Every resistor star network has a dot at one side. This side has to be placed at the crossed pin beside the red power LED. Resistor Network RN41 is not a star network. It is either realized by a 6-12 network or by two 3-6 networks. These networks are symmetric and can be mounted in either orientation.
  • Both transistors and some of the radial electrolytic capacitors have to be folded down on the controller board such that the STM32F4DISCOVERY board and the display have enough space.
  • The two 1 x 10 mounting sockets for the display have to be shortened to 1 x 9 by pinching off the last pin with a cutter and smoothing the border with a file. To ensure that the mounting sockets for the display will be correctly aligned, carefully insert the display’s pins into the mounting sockets before soldering them to the controller board, see also the hint for soldering the mounting sockets for the STM32F4DISCOVERY board.

Parts with a high mounting height

Examples: Radial inductance, radial electrolytic capacitors, terminal block, buzzer, headers for the output control, board mount sockets for the STM32F4DISCOVERY board, RJ45 jacks.

  • The positive pole of an electrolytic capacitor has a longer wire. The hole for this wires is marked by a + symbol.
  • The center pin of the 3-pin header for the test pin of the amplifier can be removed. It is not connected.
  • To ensure that the double row mounting sockets for the STM32F4DISCOVERY board will be correctly aligned, carefully insert the STM32F4DISCOVERY board’s pins into the mounting sockets before soldering the sockets to the controller board.
  • On the Buzzer there is sticking a sign marking the positive pin.
  • The IN-1 and IN-2 modular RJ45 jacks should be mounted after you already know that the GPS is working properly.

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