Welcome to the N1IR Electronics Website. Totally off the cuff, one take, unrehearsed video projects for anyone interested in amateur radio, electronic design, makers, hardware hackers and science.

Get off you duff and build something!
Training the hand and mind since 1982.

Friday, May 6, 2016


TDA7375 Power Amp Project  

Make Sure all holes are correct size
 for RCA and Green Screw Connector

 Install LEFT RCA RED connector

Install RIGHT RCA WHITE connector


Install 10 K Ohm Resistor

Install .39uF Cap

Install second .39uF Cap

 Install 47uF Cap - side left

 Install 100uF Cap

 Green Screw Connector
Open side facing LEFT

 Green Screw Connector
Open side facing LEFT
 Green Screw Connector
Open side facing RIGHT

 Green Screw Connector
Open side facing RIGHT

Install TDA7375

Mark Heatsink

 Mark Heatsink

Drill and Tap 4-10

Monday, January 18, 2016

FTDI Cable to Bluetooth HC-05 Programmer

Here is a board that can program the HC-05 Bluetooth Module using AT commands.

All that is needed is a momentary reset switch and a SPST and a resistor. Didn't bother with a PCB because it would be one of a kind to program about (40) BT Modules. With the blimp project we need to rename each module to prevent confusion, Stock name is set for HC-05.

Steps to rename HC-05 Bluetooth Module
Open the Arduino IDE
Setup correct comm port that the FTDI cable is on
Select tools and open Serial Monitor
Set for 38,400 Baud

Set Switch to PROG
Push Reset Switch to place HC-05 Board to AT Command Mode
Type AT
Should reply back OK
Should reply back HC-05
Type AT+NAME=(new name here)
Should reply back (new name here)
Set Switch to RUN
Push Reset

Schematic Coming Soon!

Monday, January 4, 2016

Engineering Academy Blimp 2016

Engineering Academy Blimp

Step 1. Place (2) 8 pin SIP Header as shown below. This is to help you properly line up the board in the next step.

Step 2. Place TB6612 H-Bridge board, IC side down. Pin 1 is PWMA

Step 3. Get Main PCB from Mr J. Pictured below

Step 4. Place (2) 14 pin SIP headers as shown, notice the the headers will not stay in place

Step 5. Place TB6612 H-Bridge board in the bottom most rows of the SIP. This will hold the SIP sockets in place so you can solder and keep pins aligned.

Step 6. Solder the four corners of the SIP Sockets, then check alignment.

Step 7. Once alignment passes, solder the rest of the pins on the SIP socket, with sharp diagonal cutters cut the LEFT SIP socket Flush to PCB. This will help the battery clip lay flat.

Step 8. Place Battery clip. And solder on the componet side of the PCB shown below

Solder POS lead

Solder NEG lead

Step 9. Unplug the TB6612 H-Bridge board and put aside. Get a BT board from Mr. J, Desolder the pins. They are facing the wrong direction

De-soldered BT Board

Step 10. Place straight 6 pin SIP, as show below, long side of the lead facing down, short side of lead plugs into board.

Step 11. File the top of the TB6612 H-Bridge board about 20 strokes, mileage mat vary. This will trim the board do it can fit next to the BT board.

Step 12. File the side of the BT board towards the SATE pin about 20 strokes, mileage mat vary. This will trim the board do it can fit next to the TB6612 H-Bridge board .

Step 13. Plug TB6612 H-Bridge board back in

Step 14. Get a 6 pin Right angle SIP connector

Step 15. Place the 6 pin Right angle SIP connector on the top right hand side on the SIP socket, this is to connect your (2) motors later.

Step 16. Plug BT board in the top left hand side on the SIP socket. If tight fit refile the boards to fit.

Step 17. Place the 6 pin Right angle SIP connector on the top left hand side of main board, this is the programming header.

Step 18. Get (2) glass beads and 16 Mhz crystal

Step 19. Place glass beads on to crystal leads, this will insulate the crystal from the top layer solder pad

Step 20. Solder in crystal, make sure the glass beads are on the leads.

Step 21. Insert (2) 22pF capacitors and solder them in

Step 22. Insert 10K ohm resistor next to Pin1 of the IC, Solder in place.

Step 23. Insert .1uF (labelled 104) capacator next to Pin 1 of the IC, Solder in place.

Step 24. Insert (2) 470 Ohms resistors, Solder in place.

Step 25. Insert LED, Long lead (+) faces the IC socket, Solder in place.

Step 26. Insert 3 pin SIP into the servo position, Solder in place.

Step 27. Insert 22uF SMT Capacitor and remove right angle SIP

Step 28. Plug in BT board

Step 29. Get (2) .01uF (labeled 103) capacitors for draw A35 in the parts room, cut one lead of the cap short.

Step 30. Thread cap though tab on motors, solder

Step 31. Cut leads flush with motor tab

Step 32. Add red/black STRANDED twisted wire (6" long") to each motor Look for the + symbol on the motor attach the red wire to this.

Step 33. Place Right angle header in helping hands

Step 34. Strip, tin and solder on the short side as shown below.
From left to right No Connection, No Connection, -M1, +M1, -M2, +M2

Step 35 Inspec and plug into main board, motors toward bottom edge.