Build guide

Relay Driver

16×28 @ 2.54mm pitch · 7 components · 9 wires

1. Prepare

Verify component pinouts against each manufacturer’s datasheet before wiring. Label cut wires with their wire numbers; the same numbers follow them through every stage. Wire colors are written out for black-and-white printing. Custom colors can be named in the wire library.

Progress is saved on this browser for this board revision. Changes to the board or measurements start a new checklist. Printed diagrams are references, not life-size templates.

9 wires to prepare; 240mm total wire, including end allowances.

Parts List

6 unique parts

Ref DesPartValueManufacturerPart NumberQtyLink
D1Diode (axial)——1—
J1Signal+Power Header (3-pin)——1—
J2Screw Terminal 2P (5.08mm)——1—
LED1LED——1Amazon
Q1NPN Transistor (TO-92)——1Amazon
R1, R2Resistor (axial)1k——2Amazon

Links may include affiliate referrals.

2. Cut wires

Cutting quantities by color and length

9 wires · +5mm per end for lead-through

Cut#NetColorRouteCut LengthBends
6COILBlackI15 → G2233mm10mm (90°)
5COILBlueJ16 → L1817mm—
4COILGreenH16 → E1618mm—
75VRedH20 → E2223mm13mm (90°)
1GNDRedE12 → E528mm—
3BASEWhiteI11 → F1421mm—
95VWhiteM10 → D546mm18mm (90°)
2SIGYellowI5 → F518mm—
85VYellowJ20 → L1138mm28mm (90°)

Total wire: 240mm (9.5in)

3. Bend wires

Use the straight-line ruler to mark bend points on the wire before bending. Use the bent shape as a visual reference while bending.

Bend ruler and shape for wire 1
Cut 28mm.
Bend ruler and shape for wire 2
Cut 18mm.
Bend ruler and shape for wire 3
Cut 21mm.
Bend ruler and shape for wire 4
Cut 18mm.
Bend ruler and shape for wire 5
Cut 17mm.
Bend ruler and shape for wire 6
Cut 33mm. Bend 90° down at 10mm.
Bend ruler and shape for wire 7
Cut 23mm. Bend 90° down at 13mm.
Bend ruler and shape for wire 8
Cut 38mm. Bend 90° right at 28mm.
Bend ruler and shape for wire 9
Cut 46mm. Bend 90° left at 18mm.

4. Place wires

Component side. Select a wire to emphasize its route in its own color and highlight its endpoints. Wires follow number order, matching the bend guide and solder checklist.

W1 · E12E5
W2 · I5F5
W3 · I11F14
W4 · H16E16
W5 · J16L18
W6 · I15G22
W7 · H20E22
W8 · J20L11
W9 · M10D5
W1 · E12E5W2 · I5F5W3 · I11F14W4 · H16E16W5 · J16L18W6 · I15G22W7 · H20E22W8 · J20L11W9 · M10D5

5. Solder connections

Bottom view: horizontally mirrored. Coordinate names still identify the same physical holes. Highlights mark wire endpoints; wire routes belong on the component side. Check each connection and the listed solder bridges.

Board is horizontally mirrored. Column A is on the right.

W1 · E12E5
W2 · I5F5
W3 · I11F14
W4 · H16E16
W5 · J16L18
W6 · I15G22
W7 · H20E22
W8 · J20L11
W9 · M10D5
W1 · E12E5W2 · I5F5W3 · I11F14W4 · H16E16W5 · J16L18W6 · I15G22W7 · H20E22W8 · J20L11W9 · M10D5