Beefcake Relay Control Hookup Guide

Pages
Contributors: MTaylor
Favorited Favorite 5

Assembly

The Beefcake Relay Control kit is relatively straight forward to assemble. This section outlines what tools will be needed and shows the assembly process.

Materials

The kit contains the following parts:

alt text

  • An electromechanical Relay
  • 2x Terminal blocks, light gauge for signal and heavy for output
  • Coil-active LED
  • Bipolar junction transistor (BJT)
  • 2x Current limiting resistors
  • Flyback arrestor diode
  • Zener diode for discharge

Tools

The following tools are recommended.

Building The Beefcake Relay Control

The Beefcake uses standard through-hole techniques. Components will be passed through the holes, soldered, and the leads trimmed. It's best to start with the shortest components working up to the taller ones. This is so they stay pressed in place while the board is upside down against a work surface.

Start with the resistors. Bend the leads so they form 90 degree angles as close to the resistor body as possible.

alt text

Feed them into the place marked 1k. They will sit over the silkscreen box.

alt text

Next, bend the diode leads. The diode bodies are shorter, so it's not necessary to get the bends right close. They should be the same widths as the resistors after bending.

alt text

Insert the diodes. The fat diode is the 9.1V zener, and should be marked 4739. Place it over the silkscreen box labled "Zener" with the black band towards the white silkscreen stripe. The smaller diode should be labled 4148 and is a standard high-speed diode. Place it over the box labled N4148 with the black stripe towards the silk stripe.

alt text

Now, flip the board, and solder those components forming nice shiny cones around the leads. A weight, like the solder stand, can be used to hold the board, or it can be placed in a vice.

alt text

Clip the component leads right at the top of the solder cones.

alt text

Next, prepare the BJT. Leave the outer two legs straight. Bend the inner leg in an 'S' curve so that it is spaced evenly from the other two legs in an equilateral triangle.

alt text

Fit the BJT and LED into the board, minding that the flat side of the LED matches the flat part of the silkscreen circle.

Solder them in place, and trim the leads.

alt text

Attach the screw terminals. Orient them so the apertures face outward. These will stay in pretty well, so flip it and solder in place.

alt text

The last component is the relay. The relay has thick leads for current capacity, so they may need a little work getting inserted. Once they are all positioned, it should sit flush with the PCB.

alt text

Inserting the relay

The extra copper involved in carrying the current means it can take extra heat to get the solder to flow, but it is very important. A cold solder joint will cause extra resistance. With the recommended Hakko iron set to 700 degrees, there should be no problem, but the iron will have to be held on longer than normal. Feed extra solder if the joint is looking dirty, the flux will come out, and you can scoop away the extra solder with the iron right after.

alt text

Notice that the iron touches both the post and the plated through hole heating them up together.

Congratulations! You now have a completed Beefcake Relay Control circuit. Here's what the final product will look like.

alt text

alt text