58 lines
1.9 KiB
Plaintext
58 lines
1.9 KiB
Plaintext
Dried Seed Timer by the Jolly Roger
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A time delay device for electrical firing circuits can be made using
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the principle of expansion of dried seeds.
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Material Required:
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-----------------
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Dried peas, beans, or oter dehydrated seeds
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Wide-mouth glass jar with non-metal cap
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Two screws or bolts
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Thin metal plate
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Hand drill
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Screwdriver
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Procedure:
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---------
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1) Determine the rate of the rise of the dried seeds selected. This is
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necessary to determine the delay time of the timer.
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a) Place a sample of the dried seeds in the jar and cover with
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water.
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b) Measure the time it takes for the seeds to rise a given height.
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Most dried seeds increase 50% in one to two hours.
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2) Cut a disc from thin metal plate. Disc should fit loosely inside the
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jar.
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NOTE: If metal is painted, rusty, or otherwise coated, it must be scraped
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or sanded to obtain a clean metal surface
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3) Drill two holes in the cap of the jar about 2 inches apart. Diameter
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of holes should be such that screws or bolts will thread tightly into
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them. If the jar has a metal cap or no cap, a piece of wood or plastic
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(NOT METAL) can be used as a cover.
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4) Turn the two screws or bolts through the holes in the cap. Bolts
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should extend about one in. (2 1/2 cm) into the jar.
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IMPORTANT: Both bolts must extend the same distance below the container
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cover.
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5) Pour dried seeds into the container. The level will depend upon the
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previously measured rise time and the desired delay.
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6) Place the metal disc in the jar on top of the seeds.
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How to use:
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1) Add just enough water to completely cover the seeds and place the cap
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on the jar.
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2) Attach connecting wires from the firing circuit to the two screws on
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the cap.
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Expansion of the seeds will raise the metal disc until it contacts the
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screws and closes the circuit.
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---------------------Jolly Roger
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