output transformer wire color codes ultra linear

Decreasing the resistance of this resistor will increase the power in the high voltage arc but stress the transistor more. This resistor will get hot! Allow space around it for airflow. I will be making a 12v driver so will reference a 220 ohm resistor from now on. Its ok to go higher in wattage rating but not lower.

Your power supply voltage determines the value of this resistor. The cheapest and nastiest stuff you can find on ebay is adequate for this, you could even salvage enough from old LED light bulbs or the TV you took the flyback from! A pea sized amount is plenty and the transistor will squash it down and spread it out. Those who are handy with metalwork could fabricate their own heatsink out of scrap by drilling the required mounting holes, just google TO-3 or TO−220 transistor technical drawing for more info.Ī thermal pad or paste/grease is recommended for better thermal transfer between the transistor and heatsink. The MJ15003 uses the TO-3 case style whilst the MJE13007 uses TO−220, TO-3 hardware is generally more expensive than TO−220. Many audio and linear application transistors possess these parameters.ġx Heatsink with mounting screws and nuts It also needs to be rated for several amps to handle the peak currents and at-least 120v, but below 250v is preferred as the higher voltage parts such often fail to oscillate in this circuit. MJE13007 also ran poorly in my tests without further circuit modifications.Ī good transistor has low turn-off delay (storage time) and fall times, decent current gain (Hfe), for example MJ15003 measures a gain of 30 with my Chinese tester. So please don't use it, if you do you'll need a large capacitor like 470-1uF across it to limit the peak voltage. The peak collector to emitter voltage easily soars above this 60v rating and clips when the transistor breaks down causing extensive heating and eventual failure of the device. The KD's are hard to get hold of cheaply these days and were more common in Eastern Europe.Ģn3055 is the classic transistor often paired with this driver on the internet, but the 60v rating limits its usefulness and more often than not results in it being destroyed. NTE284 and 2N3773 are reported to give similar performance to MJ15003 whilst KD606 and KD503 purported to work too. MJ15003 works well with this driver, it can be a little bit expensive in certain places however. TV flybacks seem to perform best with this circuit, monitor flybacks don't put out as much. Salvaged from an old CRT TV/monitor or purchased online (don't get ripped off, these things are worth about $15 tops when new). Many of these components can be pulled from old circuit boards and substitutions can often be made without issue.

Output transformer wire color codes ultra linear