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Nixie Power Board Assembly Instructions

The Nixie Power Board contains all the power regulation circuitry of the Nixie Clock. It consists of a 5V voltage regulator that converts the incoming 9V from the AC/DC adapter to a regulated 5V, which is used to power everything except the Nixie tubes.

The Nixie tubes are powered from the 180V boost converter, which steps up 9V to 180V.

The board consists mostly of pre-assembled surface mount components. To complete it we will first solder in the power jack, then test that the generated voltages are correct, and then finally solder in three cables that connect to the logic board.

WARNING: This board will generate potentially lethal voltages! Never touch the board without ensuring that power is turned off! After turning off power, wait around 30 seconds before touching the board to allow the high voltage to dissapate. When working with the Nixie clock you should take the same precautions as you would when working with live AC voltages directly from a wall socket. If you are unfamiliar with high voltage circuits, please do not assemble the board. If you feel uncomfortable with handling high voltages, please do not assemble this kit. Return it for a full refund.

 

AC/DC Adapter

The Akafugu Nixie Clock comes bundled with a universal 100-240V 9V DC power adapter with a US plug. It can be used worldwide, but will require a plug adapter for use in countries that do not use the US two-plug flat connector.

You may use any other power adapter with an output of 9V to 12V. It should be rated for an output of at least 0.5A. The plug should be 2.1mm.

Front view

Back view

Step 1 - Power jack connector

Locate the power jack connector and nut.

Now insert the connector from the back side of the power board and screw the nut back in. Note orientation. Make sure the connector stays in the middle of the hole when you screw on the nut. The connector will tend to rotate as you fasten the nut, so a flat tong will come in handy here.

First, make sure the orientation of the connector matches the picture. Now locate the two small red wires. Solder each one to the two connectors marked in the picture (leaving the third connector open).

Next, the two wires should be attached to the pads marked VIN and GND on the PCB board. Make sure the wires are connected exactly like the picture, or the board will not get power.

Step 2 - Testing voltages

Now it is time to test the voltages. For this, fasten the board in a vise, then connect the power adapter to the power jack and then plug the adapter into the wall socket.

WARNING: Make sure the board is fastened when doing voltage measurements. Be careful not do create any short circuits by accidentally touching the probes together. Doing so may damage the components on the board making it inoperable.

Step 2a - 5V

Wait a few seconds. If the board appears normal (there is no visual indication that the board is running), continue. If not, remove power.

Set your multimeter to DC voltage mode. Touch the black probe to the pad marked GND, and the red probe to the pad marked VCC. Be sure not to pysically touch the board with your hands.

The voltage should read around 5V. (It will usually be a bit lower because there is a short ciruit protection fuse on the board that lowers the voltage a bit). Anything between 4.6 and 5.4 volts is fine.

Step 2b - High Voltage

Keep the black probe on the pad marked GND. Move the red probe to the pad marked HV.

If it reads between 180V and 185V, proceed to the next step.

If it reads another value, usually between 100V and 200V, it will be neccesary to adjust the potetentiometer on the board. Remove the multimeter probes.

Use a narrow flat screwdriver and turn it a couple of turns clockwise if the voltage is less than 180V, or a couple of turns counterclockwise if the voltage is more than 185V.

Now check the GND and HV pads with the multimeter again. Repeat as neccesary until the voltage is about 180V.

Step 3 - Turn off power

Remove the probes, and turn off power. Touch the multimeter probes to GND and HV again. You should see the voltage dropping. Once it reaches 5V or less, it is safe to proceed to the next step. Take note of the time it takes to do so: You should always wait this amount of time before touching the board after removing power.

Remove the DC jack from the back of the board.

Step 4 - Logic board connector wires

Make sure that power is removed and that you have waited enough time for the voltage to dissapate.

Now locate the three long wires. Connect and solder one to each of the three pads marked GND, VCC, and HV. For now, leave them flat against the board.

It is helpful to hold the wires down using some masking tape before soldering them.

Step 5 - Nylon spacers

Locate the four long nylon spacers and four metal screws.

The screws go in from the back side of the board. Be careful when inserting and fastening the screws: The nylon spacers are easily damaged.

The power board preparations are now finished. Continue on to theControl Board Assembly Instructions.