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4. Regulator, transistor, and inputs

Now that our soldering skills are warmed up, it’s time to venture in to some of the slightly more complicated components. This section will bring us to solder the dedicated 3.3V regulator for logic voltage, as well as the transistor to boost the volume of the speaker. We will then finish off by adding the input terminals. In this section you will need the PN2222 transistor, the 3.3V regulator, the 2.2uF capacitor, the 5 position screw terminal, and the barrier block.

Insert the PN2222 transistor into Q1. The flat side of the transistor should match the flat edge of the marking on the circuit board.

Here is the PN2222 transistor inserted into Q1. Notice how the flat edges line up with the line on the silkscreen of the circuit board.

Gently bend the leads of the transistor to hold it in place when you flip the board. Then, flip the board over.
This is what the leads look like on the back of the board. Ensure that the components are still flush with the top side of the board, as it may have moved slightly during flipping.

Solder the pads with your soldering iron and solder. Then, cut the leads using diagonal cutters. Once complete, flip the board over.

Insert the 3.3V regulator into U4. See the step below for a closer photo about the orientation of this.

Here is the 3.3V regulator in U4. Note the orientation of the curved portion of the regulator.

Gently bend the leads of the regulator to hold it in place when you flip the board. Then, flip the board over.
This is what the leads look like on the back of the board. Ensure that the components are still flush with the top side of the board, as it may have moved slightly during flipping.

Solder the pads with your soldering iron and solder. Then, cut the leads using diagonal cutters.

Obtain the 2.2uF capacitor. Yours might be smaller than what is in the photo. Place it so the longer, negative, lead is touching the last pad of the regulator just soldered.

Apply tape to the capacitor to attach it to the board. Trim the leads to move the capacitor closer to the pads.

This is what the capacitor aligned with the pads looks like.

Solder the pads with your soldering iron and solder.

Here is the capacitor, now properly soldered. Once complete, flip the board over.

Insert the 5 position screw terminal into the Power Conn area. The openings need to be pointing out, towards the bottom edge of the board. The row of holes that the screw terminals go in to is the row of Z3, Z2, and Z1 – not the holes nearest to the edge of the board. Once placed, the screw terminal should not be going beyond the edge.

Here is the screw terminal inserted and in the proper orientation.

Apply some painters tape to keep the component in place. Then, flip the board over.

Solder the pads with your soldering iron and solder. Once complete, flip the board over.

Insert the barrier block into the power input area of the board.

Here is the barrier block inserted into the board in the proper orientation. Note how it is orientated so that the prongs can be easily input into the terminals.

Apply some painters tape to keep the component in place. Then, flip the board over.

Solder the pads with your soldering iron and solder. Once complete, flip the board over.
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Page last updated on: Tue Apr 7 20:25:42 2020