I’m using an instructable as reference for a project and it says to use anything available that draws 5-10A as a ballast. Examples were a hair dryer, I thin toaster, and also an incandescent bulb as a test article.
I don’t quite understand include any of those things in the circuit. Is it as simple as ripping the guts or if a hair dryer to get to the heating element and writing it in with the exposed leads?
Any general information on ballasts that aren’t for florescent lighting would be very helpful
I don’t think you can use anything as a ballast. A heating element or light bulb could function as a resistor or fuse but it’d be better to use a resistor or fuse. What’s the objective of the ballast? To limit current, to provide start up voltage, output a certain frequency of power or perhaps to provide an inductive or lagging load to counteract a capacative or leading load and manage power factor
Its purpose is current-limiting
https://www.instructables.com/Simplest-POWERFUL-Solid-State-Tesla-Coil-SSTC/
I see, the instructable suggests using an incandescent (specifically not flouro) globe wired in series with a full bridge rectifier to convert to DC. This would limit the current but is a bit ghetto and the light/heat produced is wasted energy. However a lighting ballast may not be useable as tesla coils are generally dependent on frequency. A globe or element would increase resistance as it warms as they have positive temperature coefficients. So in this case I would say wire a standard globe in series on the active side going into a rectifying diode or full bridge rectifier to convert to DC power. wire mains active to globe socket then globe neutral into diode into your circuit then circuit neutral to mains neutral. Hope this helps, best of luck (stay safe)
I just had a thought, if I’ve got a laptop charger or similar brick that supplies 5A DC, do you think there’s any reason that wouldn’t work?
I can think of three potential issues with a charging brick; The increase of resistance as a light or element warms up may actually be desirable as it would allow a higher start up current before providing stable DC Secondly, a charging brick would drop the voltage down to 12/24ish Thirdly, you won’t be able to wire it in series as you can’t share a DC negative / mains neutral on the return path if there’s transformer or different voltages
Okay, it sounds like we’re more or less on the same page and that this is more of a workaround to achieve a certain amount of amperage, but in an uncommon way, that leaves a lot up to the imagination (introducing a bit of risk)
Yes, slightly inefficient but it’s an interesting workaround. I would say just grab a plug in lamp and splice the cable on the netral but this project really should have an earth connection for safety. Grab an extension lead and a standard ceiling socket, cut the female head off the lead and mount the light socket to some timber and pass the earth through and bond to any non-live exposed metal. Smashing the light also functions as a ghetto emergency stop button :) Edit: be aware that DC suffers more voltage drop than AC, keep the lines short or use thicker cables to compensate
What are you building? (I’m trying to imaging why such a thing would be needed.)
A solid state tesla coil. It’s needed to limit current, and is wired in series with a rectifier to turn 120V AC into stable DC
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