The Listening Car AKA The Listening Tree on SteroidsAssembly And Test

Low profile parts will be installed first, starting with the simplest part of the circuit, the filters. They are located on the left end and above the IOA connector at the bottom of the board. The location on the board (when the board is oriented so that The Listening Car is right side up) is highlighted below on the left and the magnified detail on the right. This will be the case for each assembly step:

Install the four parts highlighted in red above (the same highlighting will be used from now on to indicated the parts to be installed), spread the leads a little on the back of the board, solder, then cut them. The two resistors are 10K (K means thousand) watt units (brown, black, orange). C28 is a .033uF capacitor, and C29 is a .01uF.

2Switches bounce, which can cause multiple pulses to be fed to a controller and make it see what appears to be a series of on and off pulses in rapid succession. The Debounce circuit helps clean up the switch signal. This circuit is to the left of the filter circuits as highlighted on the board outline below. Detail is on the right:

Install R17, R18 and R22, all 10K watt resistors (brown, black, orange). Install C19 and C31, .1uF ceramic capacitors. C20 is a 10uF electrolytic capacitor. Install it, being careful to get its + terminal in the right place. Spread the leads of these components, solder them and cut them close to the board.

Install the 555 IC, designated DeBounce on the board, and solder it in. Be sure to get pin 1 to the left (the square pad). Slightly bend 2 pins on diagonal corners to hold it in before soldering.

3At the bottom right of the board are some simple Sample Hold circuits, or at least that's what I call them, even though they don't exactly qualify for the real thing, as will be explained in the circuit description.

The board location of the Sample Hold circuits is highlighted in yellow below, and the detail is on the right:

Install the 1N4148 diodes D7, D8, D9 and D10. Make sure they are correctly polarized by installing them with their stripes to the right. Install the 10uF/25V electrolytic capacitors C24, C25, C26 and C27. Make sure the positive sides are oriented as shown. The resistors in the circuits are contained in a resistor array, which is the rectangle below the IOB connector above. GND (ground) is on the right end, which is pin 1. Pin 1 commonly has a dot at that location as shown above. The pad for pin 1 on the board is square.

4There are three voltage regulators on the board. One is for +5 Volts, and is located just below the Device 3 channel. The following shows the board location and detail:

The 7805 regulator looks like this from the front:

Install it with the metal back of the regulator to the right as shown, then solder it in and cut the leads on the back near the board. Install C9, a .1uF ceramic capacitor and C10, a 470uF electrolytic, watching the polarity for C10, then solder and cut their leads near the board. Attach a small heatsink such as the Jameco 326596 sideways to avoid C10, with the fins pointing to the outside of the board.

5There is also a +9 Volt switching regulator. It gets its input from the +5 Volt regulator to keep down noise, and is just below the +5 Volt regulator section:

Install R11, a 10K watt resistor (brown, black, orange), R12, a 180 ohm watt resistor (brown, gray, brown), R13, a 3 ohm watt resistor (orange, black, gold) and R14, a 62K watt resistor (blue, red, orange). Spread their leads a little on the back, solder them in and cut them near the board.

Install D5, a 1N5819 Schottky rectifier, paying close attention to the stripe, which should be to the right. Install Z5, a 1N4744 15 Volt zener diode, making sure the stripe is to the left. Spread their leads a little on the back, solder them in and cut them near the board. Continue assembly of this regulator on the next page.

6Install C11, a 470pF ceramic disc capacitor and C13 and C14, both 470uF/25 volt electrolytic capacitors, spread their leads a little on the back, solder them in and cut them near the board. Note the polarities for C13 and C14.

Install inductors L1 and L2 in a similar manner. There are no polarity concerns for the inductors.

Install the 34063 regulator IC (designated Pos9Reg), making sure that pin 1 is to the left (square pad). Bend two diagonal pins over a little to hold it in, then solder it in.

Assembly of the next section begins on the next page.

7There is a -9 Volt regulator in the bottom left-hand corner:

Install R15, a 62K watt resistor (blue, red, orange), R16, a 10K watt resistor (brown, black, orange) and R19, a 3 ohm watt resistor (orange, black, gold). Spread their leads a little on the back, solder them in and cut them near the board. Continue on the next page.

8Install D6, a 1N5819 Schottky rectifier, paying close attention to the stripe, which should be to the right. Install Z6, a 1N4744 15 Volt zener diode, making sure the stripe is to the right. Spread their leads a little on the back, solder them in and cut them near the board.

Install C15, a 470pF ceramic capacitor and C17 and C18, both 470uF/25 volt electrolytic capacitors, spread their leads a little on the back, solder them in and cut them near the board. Note the polarities for C17 and C18.

Install inductors L3 and L4 in a similar manner. There are no polarity concerns for the inductors.

Install the 34063 regulator (designated Neg9Reg), making sure that pin 1 is to the left (square pad), bend two diagonal pins over a little to hold it in then solder it in.

Assembly of the next section begins on the next page.

9Install the two Input/Output connectors on the bottom of the board:

Bend the end pins out a little to hold them in before soldering There are no polarity considerations to worry about.

The next steps will be to install the low profile parts in the device driver sections. One main difference between these sections and the ones above is that in these sections some of the wires will not be cut. They will be used to increase the current carrying capability of the driver section board traces later on. Assembly begins on the next page.

10We will begin with the Device 1 section, located at the top-left of the board:

Install R1, a 180 ohm watt resistor (brown, gray, brown) and R2, a 10K watt resistor (brown, black, orange) and spread their leads a little on the back to keep them in. Do not solder them in yet. Install the GI-1.5KE36CA Transient Voltage Suppressor (TVS1) and spread its leads in a like manner. Its stripe is up. Do not solder it in yet. Install C1, a .1uF ceramic capacitor, and C2, a 10uF/25V electrolytic capacitor, making sure to correctly polarize C2. Spread their leads slightly to hold them in, solder them and cut them close to the board. Install Z1, a 1N4744 zener diode with its stripe to the left as shown, then bend its wires a little to hold it in, solder them and cut them. Install D1, a 1N5819G Schottky diode with its stripe to the right as shown, then bend its wires a little to hold it in, solder and cut them. Hold on to the wires cut off for later. Install the 4420, bending two diagonal pins over a little to hold it in, making sure its pin 1 is to the left. Solder it in.

11Similarly, install the low profile parts for the Device 2 section, just below Device 1:

Install R3, a 180 ohm watt resistor (brown, gray, brown) and R4, a 10K watt resistor (brown, black, orange) and spread their leads a little on the back to keep them in. Do not solder them in yet. Install the GI-1.5KE36CA Transient Voltage Suppressor (TVS2) and spread its leads in a like manner. Its stripe is up. Do not solder it in yet. Install C3, a .1uF ceramic capacitor, and C4, a 10uF/25V electrolytic capacitor, making sure to correctly polarize C4. Spread their leads slightly to hold them in, solder them and cut them close to the board. Install Z2, a 1N4744 zener diode with its stripe to the left as shown, then bend its wires a little to hold it in, solder them and cut them. Install D2, a 1N5819G Schottky diode with its stripe to the right as shown, then bend its wires a little to hold it in, then solder and cut all three. Hold on to the wires cut off for later. Install the 4420, bending two diagonal pins over a little to hold it in, making sure its pin 1 is to the left (square pad). Solder it in.

12Similarly, install the low profile parts for the Device 3 section to the right of Device 2:

Install R5, a 180 ohm watt resistor (brown, gray, brown) and R6, a 10K watt resistor (brown, black, orange) and spread their leads a little on the back to keep them in. Do not solder them in yet. Install the GI-1.5KE36CA Transient Voltage Suppressor (TVS3) and spread its leads in a like manner. Its stripe is down. Do not solder it in yet. Install C5, a .1uF ceramic capacitor, and C6, a 10uF/25V electrolytic capacitor, making sure to correctly polarize C6. Spread their leads slightly to hold them in, solder them and cut them close to the board. Install Z3, a 1N4744 zener diode with its stripe to the right as shown, then bend its wires a little to hold it in, solder them and cut them. Install D3, a 1N5819G Schottky diode with its stripe to the left as shown, then bend its wires a little to hold it in, then solder and cut them. Hold on to the wires cut off for later. Install the 4420, bending two diagonal pins over a little to hold it in, making sure its pin 1 is to the left (square pad). Solder it in.

13Similarly, install the low profile parts for the Device 4 section above Device 3:

Install R7, a 180 ohm watt resistor (brown, gray, brown) and R8, a 10K watt resistor (brown, black, orange) and spread their leads a little on the back to keep them in. Do not solder them in yet. Install the GI-1.5KE36CA Transient Voltage Suppressor (TVS4) and spread its leads in a like manner. Its stripe is down. Do not solder it in yet. Install C7, a .1uF ceramic capacitor, and C8, a 10uF/25V electrolytic capacitor, making sure to correctly polarize C8. Spread their leads slightly to hold them in, solder them and cut them close to the board. Install Z4, a 1N4744 zener diode with its stripe up as shown, then bend its wires a little to hold it in, solder them and cut them. Install D4, a 1N5819G Schottky diode with its stripe to the left as shown, then bend its wires a little to hold it in, solder and cut them. Hold on to the wires cut off for later. Install the 4420, bend two diagonal pins over a little to hold it in, making sure its pin 1 is to the left (square pad). Solder it in.

14The next step will be to install the input terminal blocks, TIP120 transistors and input capacitors, as shown below (the board illustration is segmented to save space):

Install the 4 position terminals which are constructed using two 2-position terminals attached to each other. Make sure the side that accepts wire faces the outside of the board before soldering. The 2 position blocks fit together by means of little slide-together sections on the sides. Push the board down on them on the table to hold them in place while you solder. You could also skip this step and solder wire directly to the terminal holes if you wish, which is a good idea for applications where there is significant vibration:

15Install TIP120A, a TIP120 darlington transistor with its metal side toward InCap1. Bend its two end tabs on the back a little to hold it in, then solder and cut all three.

Install TIP120B, a TIP120 darlington transistor with its metal side toward InCap2. Bend its two end tabs on the back a little to hold it in, then solder and cut all three.

Install TIP120C, a TIP120 darlington transistor with its metal side away from InCap3. Bend its two end tabs on the back a little to hold it in, then solder and cut all three.

Install TIP120D, a TIP120 darlington transistor with its metal side away from InCap4. Bend its two end tabs on the back a little to hold it in, then solder and cut all three.

Install the 1000uF/50V input capacitors designated InCapn, where n is the device number, taking care to observe polarities. Solder and cut the wires.

16Install C16, C22, C30 and C23, all 1000uF/50V capacitors, taking care to observe polarities. Slightly spread their wires to hold the caps in, solder them and cut the wires:

Assembly continues on the next page.

17Stick some electrical tape on the bottom of the heatsinks to insulate them from the board. Punch a small starter hole in the tape, then push the pins through the tape with the sticky side of the tape toward the heatsink. Trim the tape so it just covers the bottom of the heat sink columns:

18Now mount the MOSFETs (Metal Oxide Semiconductor Field Effect Semiconductor Transistors) to their heatsinks, being careful to avoid static discharge:

Coat both sides of the mica insulator with thermal grease. Put the machine screw through the insulated bushing, then through the hole in the MOSFET, then through the mica insulator and finally through the middle hole of the heatsink. Then place the metal washer on the screw on the back of the heatsink, then the nut. Tighten only thumb tight.

Mount the heatsinks on the board with the MOSFETs facing the edge of the board. Make sure the heatsinks are flat on the board, then solder the heatsink pins to the board. This might take a little higher power iron than the other devices. Do not solder the MOSFET pins yet. That part will begin on the next page.

19The next step will be to increase current capability by using the wires that were not cut and the scraps you saved. We will start with the Device 1 channel. Shown below is the back of the board where Device 1 is located. Part designators have been added for reference. Bend the drain tab of the MOSFET to the right, and the source tab downward. Bend over or place wires where the red lines are shown over the board traces below (not pretty on purpose so you will know your wires don't need to be use some Solder Wick in the place of the wires to make it neater). Then solder the wires to the traces and pad locations, coating the pads, traces and wires with solder. Doing so will increase the current capability of the circuit:

20Do the same thing with the Device 2 channel. Shown below is the back of the board where Device 2 is located. Part designators have been added for reference. Bend the drain tab of the MOSFET to the right, and the source tab downward. Bend over or place wires where the red lines are shown over the board traces below. Then solder them to the traces and pad locations, coating the pads, traces and wires with solder:

21Do the same thing with the Device 3 channel. Shown below is the back of the board where Device 3 is located. Part designators have been added for reference. Bend the drain tab of the MOSFET to the left, and the source tab up. Bend over or place wires where the red lines are shown over the board traces below. Then solder them to the traces and pad locations, coating the pads, traces and wires with solder:

22Do the same thing with the Device 4 channel. Shown below is the back of the board where Device 4 is located. Part designators have been added for reference. Bend the drain tab and the source tab of the MOSFET to the left. Bend over or place wires where the red lines are shown over the board traces below. Then solder them to the traces and pad locations, coating the pads, traces and wires with solder. Doing so will increase the current capability of the circuit:

Finally, make sure all tabs of all four MOSFETs are soldered and tighten the screws holding them to their heat sinks. Solder and cut the leads of components not used in the current enhancement process. Cut the metal machine screws holding the MOSFETs in or bend the TIP120s over a little so they won't touch the screws. Construction is completed. Now, that wasn't too bad, was it? We will now test the basic operation of a Listening Car board and look at some ideas about how to hook one up.

23Checking For Proper Electrical Operation

Due to space constraints, abbreviations had to be used for the Input/Output connectors IOA and IOB. They are translated as follows:

Board Abbreviation Actual UseGND GroundSH4O Sample Hold 4 OutSH3O Sample Hold 3 OutSH2O Sample Hold 2 OutSH1O Sample Hold 1 OutSH4I Sample Hold 4 InSH 3 IN Sample Hold 3 InSH 2 IN Sample Hold 2 InSH 1 IN Sample Hold 1 InPWM4 PWM Device 4 InPWM3 PWM Device 3 InPWM2 PWM Device 2 In

PWM1 PWM Device 1 In5V +5 Volt Regulator Out+9V +9 Volt Regulator OutGND Ground-9V -9 Volt Regulator OutHPO High Pass OutHPI High Pass InLPI Low Pass InLPO Low Pass OutDBO Debounce OutDBI Debounce InGND Ground

24Begin testing by connecting a 12 volt power DC supply to one of the device channels. An old computer supply or wall wart will work just fine. For the test, connect power to only one section at a time:

Now check for proper voltages on the IOA connector. You should get fairly close to +5, +9 and -9 volts at the points shown, with the common side of the meter connected to GND. Check for incorrect wiring if anything is more than about +/- 5% off, especially the 5 volt section if you plan to run a controller off of it:

You should also see around 10 or 11 volts on pins 1 and 8 of the 4420 driver of the section to which you have connected the 12 volt power supply:

Follow the same procedure with the other three device sections. Check all rectifiers, especially D1, D2, D3, D4, D5 and D6, and electrolytic capacitor polarities if you do not get +5, +9 or -9 volts for any of the device channel.

25Make the following connections to perform a basic test on all device channels. A single 12 volt power supply can be used, or multiple power supplies where that is appropriate. When using a single supply, use low power lights so the power supply will not need to be too large for the first test. One example might be an instrument light from an auto supply house, such as the Blazer 168R, G and B (red, green, blue) series. Get a white one for the 4th channel:

The wires on the lamps can be carefully bent out from the body to allow the wires to be directly inserted into the device/drain terminals. Individual LEDs could also be used. Just connect a 470 ohm resistor from the Device terminal to the long wire of the LED, and the short wire of the LED to the Drain terminal. LED light strips are also a good test if you have them. Some of the Jameco units come with their own power supplies. The single supply wiring is shown below:

26Simply connect all Vin terminals together and all GND terminals together when using a single supply, then connect the power supply to any Vin and GND.

A simple UNO program will be used to test all of the channels at once.

Connect PWM1 on the Listening Car board to pin 6 on the UNO, PWM2 to pin 9 on the UNO, PWM3 to pin 10 on the UNO and PWM4 to pin 11 and GND to GND on the UNO (PWM means Pulse Width Modulation more on that later).

Make sure the UNO is working by running the blink program (Arduino calls programs sketches, which makes sense since some of the programming is hidden to make life a little simpler). Copy or download the following to test the circuit. Downloading is easier. Just highlight all of the downloaded document then press Ctrl C (in Windows) to copy. Then, in the Arduino interface, click Edit/Select All, then Edit/Paste. Then click File/Save As. Save it to an appropriate name (mine are a tad long you can probably come up with shorter ones that mean something to you). The program, listed on the next page, simply turns on each of the devices one at a time for one second, then turns on all three for three seconds, then repeats the whole thing. You will hopefully see something like this using Blazer lights (the choppiness on the end is me, not the program or board also, I used red for both Device 1 and 4)./* ListeningCarAllDevicesTest Turns one light on 1 second, then next, etc. */

int Light_1_Pin_6 = 6, Light_2_Pin_9 = 9, Light_3_Pin_10 = 10, Light_4_Pin_11 = 11;

void setup(){

pinMode(Light_1_Pin_6, OUTPUT);pinMode(Light_2_Pin_9, OUTPUT);pinMode(Light_3_Pin_10, OUTPUT);pinMode(Light_4_Pin_11, OUTPUT);

}

// Page 27 of text not part of program or comments, but no problem if left invoid loop(){

// 255 is full on, 0 is off in this modeSetLED(255, 0, 0, 0, 1000); // 1 on, 2 off, 3 off, 4 off 1 secondSetLED(0, 255, 0, 0, 1000); // 1 off, 2 on, 3 off, 4 off 1 secondSetLED(0, 0, 255, 0, 1000); // 1 off, 2 off, 3 on, 4 off 1 secondSetLED(0, 0, 0, 255, 1000); // 1 off, 2 off, 3 off, 4 on 1 secondSetLED(255, 255, 255, 255, 3000); // all on 3 seconds

} // end void loop()

void SetLED(int Light_1_Value, int Light_2_Value, int Light_3_Value, int Light_4_Value,int DelayTime)

{analogWrite(Light_1_Pin_6, Light_1_Value);analogWrite(Light_2_Pin_9, Light_2_Value);analogWrite(Light_3_Pin_10, Light_3_Value);analogWrite(Light_4_Pin_11, Light_4_Value);

delay(DelayTime);

} // end void SetLED(..)

// end ListeningCarAllDevicesTest

The heatsinks should remain cool with the automotive lights, the LEDs and the LED strips. The same will be true of an Eiko MR16, 50 watt, 12 volt Halogen bulb if everything is wired correctly (I got a socket with wire pigtails on it for mine at an auto supply). The bulb itself, however, runs anything but cool. Halogens get very hot. One of my volt meters is no longer with us due to the fact that I laid a Halogen on it while testing the Listening Car.

A device driver heatsink remained cool with two Halogens. It only got close to too-warm-to-touch with 4 50 watt Halogens. That's 200 watts per channel, which is a little over one horsepower with all four channels operating. Use larger heatsinks to get maximum power.