This is

Fused Relay Block


Copyright © 2013 William Robison

Schematic Image

This is a Fused Relay control board for adding aftermarket headlamps.


Schematic Image
PCB Package

Schematic Image
PCB Package

J1, Power

Middle pin of the 5-pin connector (pin 3) is the battery input pin.
End pin (pin 5), on the right, is the ground connection.
The right 2 pins are from R1 providing both normally open and a normally closed connections.
The last connection, on pin 4, is the normally open pin from relay R2. This relay may be configured to switch either power or ground. Ground is switched by movinf the fuse from the "F2" position to the "F3" position.
This set of connections are terminted with #6 studs installed directly on the board. If we can find brass machine screws, they may be sopldered to the board to improve conductivity.

The power pads are 0.375" diameter and are spaced 0.500 apart.

Ring Terminals for 12/10 AWG wire #6 or 3.5mm. These part numbers have a narrow ring (less than 0.290 diameter) to allow adequate clearance on the board and they are not insulated (so they require heat shrink after crimping & soldering).

        TE Connectivity 34892   Mouser   Digikey  
        TE Connectivity 2-35476-1   Mouser   Digikey  
        Molex Inc 0190690232   Mouser   Digikey  
        Molex Inc 0190690232   Mouser   Digikey  

J10, Control

The control connecion is using a simple screw terminal block with 65 connections. 12 volts and ground are on the ends (+12V on pin 1 and GND on pin 6).
The two coil terminals from each relay are presented on the connector allowing flexibility in the control connections.
The 12 volt line is fused with F10 (nominally 5 Amps fuse)
Spare pads are provided on the +12V and GND nets to allow connections to be made directly on the bottom of the board.

Screw Terminals (0.200" pitch)

        TE Connectivity 282841-6   Mouser   Digikey  
        TE Connectivity 282857-6   Mouser   Digikey  
        FCI 20020316-H061B01LF   Digikey  
        Phoenix Contact 1730654   Mouser   Digikey  
        Molex Connector Corporation 39544-3006   Mouser   Digikey  

R1/R2, Relay

Relay sockets are required as the board is drilled for round pins.

FUSE_02 Relay: G8JN-1C6T-R-DC12   Mouser   Digikey   (35A)
FUSE_02 Socket: VCF4-1000           Mouser   Digikey

VCFM_02 Relay: VFMA-15F41-S01   Mouser   Digikey   (25A)
VCFM_02 Socket: VCFM-1000           Mouser   Digikey


Fuse Holder (socket)   Mouser   Digikey
ATC Fuse 5A   Mouser   Digikey
ATO 257 Fuse 5A   Mouser   Digikey
ATO 257 Fuse 10A   Digikey
ATC Fuse 15A   Digikey
ATO 257 Fuse 15A   Mouser  
ATC Fuse 20A   Mouser   Digikey
ATO 257 Fuse 20A   Digikey
ATO 257 Fuse 25A   Mouser  

Diodes D1/D2

Pads are provided for mounting a diode or resistor across the coil on the bottom of the board. This is to allow the board to be controlled using a FET or Transistor. .

PAC-TEC Enclosures

These aren't carried by Digikey.

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