I'm designing a circuit in which current periodically passes through a copper coil (with an air core), which acts as an electromagnet. The resultant magnetic field then repels a neodymium magnet attached to a rod, such that when the current stops, the magnet+rod returns to its original position.
In the circuit I'm presently trying (below), the periodic output from a 4060 counter is amplified by a BC547 NPN transistor, which then charges a relay that switches 9 volts through the coil. The power supply is a Mastech benchtop HY3005f-3.
I'm presently using quite thick wire (24 SWG, 0.56 mm), and so the resistance of the coil is only 0.5 ohms, which gives a large enough current to do the job (the magnetic field of an electromagnet is a function of both the current in the coil and the number of turns in it). However, the problem is that the power supply sees the coil as a short circuit, and so the short circuit protection in the supply is activated whenever the coil is charged. One way around this is would be to wind the coil with thinner wire and more turns, so that it has a sufficiently high resistance to not appear as a short circuit to the supply.
My question is, is there a way to design the circuit so that I can keep using my present, low resistance, coil without the supply seeing it as a short circuit? Perhaps by discharging a capacitor through it? Or is the only way to go with thinner wire and more turns?