by Scot Heath
Overview:
This goal of this design was a simple, rugged control which operated on common
120VAC and met the requirements set forth in the FITA rules for time and
simultaneous horn/light operation. In addition, it was desired to have the horn
be used to run the shooting line and have the time selectable for 3 arrow (2
minute) and 6 arrow (4 minute) ends.
Electrical:
The control uses industrial grade switches and relays available from most
electrical supply houses. For the control pictured, the supplies were purchased
at the vendors listed in the bill of materials.
Bold lines on the schematic should be 16 gauge or larger wire, non-bold lines
can be smaller control wire such as 22 gauge.
Schematic
Bill of materials | ||||
catalog number | description | price each | quantity | total |
From Grainger | ||||
1XC31 | Quad outlet cover | $1.39 | 2 | $2.78 |
2X464 | SPST toggle switch | $3.82 | 2 | $7.64 |
4E233 | TDPU solid state relay,600 seconds | $8.23 | 3 | $24.69 |
4KP29 | 8"x8"x6" Junction box,p366 | $20.18 | 1 | $20.18 |
5A050 | Quad box | $1.43 | 2 | $2.86 |
5ZC16 | 4 pole double throw general purpose relay | $4.41 | 3 | $13.23 |
5ZJ21 | Relay socket | $7.01 | 3 | $21.03 |
6HT08 | Black momentary push button switch | $4.75 | 1 | $4.75 |
6HT13 | Green momentary push buton switch | $4.75 | 1 | $4.75 |
6HT49 | Red momentary mushroom switch | $10.71 | 1 | $10.71 |
6HX27 | Single NO switch contact block | $9.09 | 1 | $9.09 |
6HX29 | Single NC switch contact block | $9.09 | 1 | $9.09 |
6HX35 | Dual NC switch contact block | $15.86 | 1 | $15.86 |
3k | 10 watt resistors | $0.90 | 2 | $1.80 |
Sub Total | $148.46 | |||
From Home Depot/Mountain States Electronics/Ebay | ||||
#6 nuts | $2.53 | 1 | $2.53 | |
#6 screws, 1" | $0.98 | 2 | $1.96 | |
#6 screws, 3/4" | $0.98 | 2 | $1.96 | |
1/2" grommet | $1.29 | 1 | $1.29 | |
100 watt flood light bulb | $7.97 | 3 | $23.91 | |
40 watt light bulb | $2.99 | 3 | $8.97 | |
duplex outlets | $0.39 | 4 | $1.56 | |
handle | $1.67 | 2 | $3.34 | |
hinges | $2.19 | 1 | $2.19 | |
horn | $6.00 | 1 | $6.00 | |
light bulb sockets | $1.19 | 3 | $3.57 | |
resistor | $0.90 | 2 | $1.80 | |
spade terminals | $0.97 | 4 | $3.88 | |
strain relief | $1.39 | 1 | $1.39 | |
wire, 100' 16 ga extension cord | $6.91 | 4 | $27.64 | |
wire, 15' 16 ga extension cord | $2.79 | 3 | $8.37 | |
wire, 25' 16 ga extension cord | $3.99 | 1 | $3.99 | |
wire, 9' 16 ga extension cord | $1.69 | 4 | $6.76 | |
alarm horn | $25.00 | 1 | $25.00 | |
Sub Total | $136.11 |
Mechanical
The box used to house the control is steel and measures 8" wide by 8" long by 6"
deep All the components are mounted to the bottom of the box except the switches
which are on the lid and the outlets which are in standard quad steel boxes on
the outside. Note the plastic grommets in the holes between the main enclosure
and the outlet boxes:
Light box:
The light box is constructed such that the 100w flood lamps illuminate the white
painted lid which is propped open at 45 degrees. The box may be placed either
horizontally or vertically. A design improvement would be to make the box a bit
deeper, perhaps 50%, so that the lights could be placed closer to the shooters
without the lights being visible directly.
The back of the light box is left open at the bottom for cooling and for cord
exit. The supports fold down, the cords fit inside and the lid secures for
transport via the two thumb screws shown. The front of the box is ¾" thick while
the sides are ½". This protects against arrow strikes while keeping the box
light enough for easy transport. The horn is installed in the end of the box
which is away from the camera, you can just see the mounting over the top of the
red bulb in the photo above.
Operation:
Notes:
You won't find a fuse in the photos, I added it to the schematic later. The
enclosure is steel and is grounded and for catastrophic faults, the wall outlet
is must be protected by code. Probably not a good idea to leave the control
connected if it's unattended. If you choose to leave out the fuse, you're on
your own.
The bill of materials shows cords, bulbs and sockets that don't appear to match
up to the parts pictured. That's because some scrap was used, we also have a
small light board for the 9 meter shooters, and the bill of materials was
developed for reimbursement purposes.
It is time consuming to set the time delay relays accurately. An
alternative is to use digital switch set relays from ICM, model 103B, which has
the same pin outs.
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