With Instructables you can share what you make with the world, and tap into an ever-growing community of creative experts.
Tell us about yourself!
Nice to see young people get involved in Electronics, learning the ropes as to say in a "hands on" way. He has the basic concept. They must be encouraged, hopefully they'll become tomorrows innovative "think out the box " engineers of which we have too few nowadays.
Interesting reuse of a Ballast Transformer. I imagine from the core size it may handle about 100 -200 Watts, but it really depends on the wire sizing of the winding's, isolation material and exact core details. So it would have been good to inform us of the maximum continuous current / wattage he managed without the core overheating, excessive secondary voltage drop. This is simple to do.Cannot be sure of how much isolation you actually have though. This is really important to know. The Primary & Secondary winding's are separated, that is a positive due to physical separation distance. But it also will depend on the isolation of the winding's to the core and to each other. It will probably give some isolation. But you really really need to know how much. The way to check this is performing a Hi Pot test between winding's and winding's and core. You can use a simple Megger to do a basic Hi Pot test. But please don't rely on this Transformer for serious safety use, especially for outside use as the housing is not sealed adequately which means if the it get wets, you may end up with no isolation and an even worse shock hazard due to 200V winding tap. The most common reason to use a Isolation Transformers is to to provide Galvanic isolation to people from AC Utility supply ground returns for safety reason. ie. Domestic utility AC supply Neutral is usually close to or the same as the ground potential. So defective equipment with an isolation fault to Hot may lead to human contact and a flow through the body to another part of the body connected to ground. A good isolation transformer avoids this. Obviously it still has a dangerous potential on the output but it avoids the ground loop issue. Modern GFI's do not isolate, they merely trip the power when a current from HOT to ground is exceeded. A shock will still happen, but due to it's momentary nature it is unlikely to cause death or serious injury to most people. Until Modern GFI's became available the use of isolation transformers for AC powered power tools inside was and probably for outside work is still highly recommended even mandatory for commercial professionals is some countries. And highly advisable even mandatory to use Isolation Transformers for AC powered hand tools outside, even on generator sets. In Electric Power Stations because of the various high potentials generated and the possibility to connect to them it through Ground it is still mandatory in some countries to use Isolation Transformers. I seem to remember in the UK where domestic power is 240VAC, that in UK power stations they could only use 120VAC power tools connected through a certified 240V to 120V Isolation transformers with certified isolated 120V power tools. This may have changed somewhat with the recent availability and popular use of battery powered hand tools. Note: I used AC power tools as an example due the obvious physical contact using them involves, but it still will apply to any AC mains powered Test Equipment, and all other electrical equipment where physical contact is involved as well. Medical instrumentation is another very specialized field where electrical isolation is very important, this has other criteria beyond scope of a simple discussion like this.
Join 2 million + to receive instant DIY inspiration in your inbox.
Download our apps!
© 2016 Autodesk, Inc.