How to wind spiral

Nichrome spiral is the main element of many heating devices. Nichrome after cooling retains plasticity, so the spiral of this material can be removed, to change its shape to fit the desired size. In industrial conditions the winding spiral is carried out automatically. If you decide to exercise at home manual winding, first of all, you need to make certain minimum payments.

You will need

• - nichrome wire:
• - copper or aluminum wire;
• - rod;
• - machine for winding.

Instruction

1. If you are not too interested in the parameters of the finished work of spiral in her condition, make when winding calculation "by eye". To do this, pick up the required number of turns depending on heating nichrome wire periodically including a spiral in the network, and increasing or decreasing the number of turns. This procedure of winding simple, but it can take considerable time; with the portion of the nichrome is spent in vain.
2. To improve the efficiency, accuracy and ease of calculation of winding spiral use the special table (see drawing). The table allows to calculate the length of the winding turn to turn depending on the diameter of the rod on which it is winding. Also taken into account the resistivity of nichrome wire and thickness of wire. The table shows data for a mains voltage of 220 V.
3. Knowing the original settings of your existing nichrome wire, make a simple mathematical proportion. For example, you want to determine the length of the winding of nichrome spiral wire with a thickness of 0.3 mm at a voltage of 127 V. Suppose the rod diameter for winding equal to 4 mm. At the table, find the length of a spiral, designed for a voltage of 220 V (it is equal to 22 cm). Make the ratio:
   22 cm – 220 V;
   
   Cm - 127;
   
   Thus:
   
   X =127 x 22 / 220 = 12,7 cm
4. Calculate the required number of turns, turn to wind onto the rod. Not cutting the wire, carefully connect the nichrome spiral to the source voltage. Check the correctness of their calculations for winding spiral. Note also that for closed spirals the length of the winding should be increased by one-third of the values listed in the table.
5. To ensure the same distance between adjacent turns, keep winding in the two wires. One of the wires – nichrome, and as a second use any copper or aluminum wire with a diameter equal to the desired gap. At the end of winding of the spiral auxiliary coil the wire neatly.
6. If you want to give nichrome wire required winding tension of the spiral heat it current. For this, the findings of the current source connect with the portion of winding nichrome wire, which is directly adjacent to the terminal. The contact connection must be moving (you can use carbon brushes from the motor).