steven Posted October 13, 2005 Author Report Share Posted October 13, 2005 audio guru i did use current limiting resister but at more than what the led with biult in current limiting resister can tollerate as like in the one transister version capacitor charge indicater the 1/4 watt just burns out so i use 1k at 1/2 watt Quote Link to comment Share on other sites More sharing options...
steven Posted October 13, 2005 Author Report Share Posted October 13, 2005 :)the latest exsperiment im working on is a simple ring launcher exsperiment so as soon as ive got it all together and if it even flys a few inchers its good enougth to post it then , and powerd from the high voltage photo flash capacitor charger allso electro charger to seem that it can charge them up to , and seem that it works for a short coil gun i hope it works for the ring launcher , which if it works will be the simplest and smallest and shortest ring launcher on the net Quote Link to comment Share on other sites More sharing options...
steven Posted October 25, 2005 Author Report Share Posted October 25, 2005 :)after ive discharged the charged up non photo flash capacitor into my first coil gun ive noticed that the capacitor still seems to hold a small charge even when its suposed to be discharged , a serch on the net for anserws , and ive come up with some mention about useing a led and resister to indicate this residual charge left in the capacitor , anyhow i dident bother with the resister but i tried touchiong just the bare bones led to the capacitor and it blinked briefly without being destroyed, so the small voltage in it was now all gone but i wonder why was it there when i exspected it to be all discharged, Quote Link to comment Share on other sites More sharing options...
audioguru Posted October 25, 2005 Report Share Posted October 25, 2005 Capacitors have a parameter called "dielectric absorption" which causes a voltage to develop across them after they have been discharged. Electrolytic capacitors especially have this problem. It messes-up the biasing of transistors or opamp circuits which causes distortion. Quote Link to comment Share on other sites More sharing options...
steven Posted October 26, 2005 Author Report Share Posted October 26, 2005 :)its funny you should say that audio guru , the only transister in the high voltage photo flash capacitor charger is the irf 540 n channel mosfet and the only ic is the timer and the rest are just resisters and caps Quote Link to comment Share on other sites More sharing options...
steven Posted November 13, 2005 Author Report Share Posted November 13, 2005 :)while the latest high voltage photo flash cap charger ,with large 4700uf 250 volts electro, for dishargeing and chargeing, is under construction , here is the latest, an ignition coil version high voltage photo flash cap charger . now i made a slight modification to the simple ignition coil driver circuit, i added a 0.1uf green cap from pin 4 position on the main board to the bottom neg rail. it is marked as 104, to convert that look at the capacitor conversion chert i posted some time ago. now the ignition coil version cap charger was my single arc output type that has no return as it goes to ya finger and i used it to exfoiliate freckels or surface skin . so i modified it to charge capacitors with. now i used the same circuit as i did with the other version high voltage photo flash cap charger, not the driver circuit but the parts i used to it to be able to charge up the capacitors with now the diode string idea i was trying was no good so i added a 330k 1/4 w resister from the hv out of the coil to the terminal and from there i threw in the rest the same as i did with other cap charger well you will see the difference here , Quote Link to comment Share on other sites More sharing options...
steven Posted November 13, 2005 Author Report Share Posted November 13, 2005 :)here is what it looks like now . the 330k reister you cant see as the leads are in the way this unit used to have a modified high voltage polarity indicater in it , useing diodes rated at 15kv each from microwave ovens , but i took it out to do the leatest modifications, Quote Link to comment Share on other sites More sharing options...
steven Posted November 13, 2005 Author Report Share Posted November 13, 2005 :)in the latest here ive made a few home made pvc 1n4508 diode holders as youll see so theres no crambing or parts on any board Quote Link to comment Share on other sites More sharing options...
steven Posted November 13, 2005 Author Report Share Posted November 13, 2005 :)if you zoom in on the positive output terminal inside the box you may see the 330k 1/4 watt resister. here is the front of the cap charger and the neon is protrudeing out the white pvc pannel peace so ill be modifying that next time so it will be a green charge indicater light , by modifying a few 12 volts power indicater lights and useing a neon inside the globe houseing. ive done this allready and have 2 installed on the other unfinished cap charger that i will post when done Quote Link to comment Share on other sites More sharing options...
steven Posted November 13, 2005 Author Report Share Posted November 13, 2005 :)here are some of the test results; photo flash caps with there lower uf values seem to take less time to charge up and the higher the value the longer it takes but the results are rewarding when you short them out and get the big bang , the neon charge indicater gets reallybright when the cap is charged up , and if i charge up my 1200uf 200 volts cap with its protection diode and neon with its resisters the first neon to come on is the one in the charger itself the neon on the cap will take longer to come on with this particular circuit but the one on the unit that comes on at its brightest would be the best one to go by rarether than waiting for neon number 2 to come on which means i would have to let it charge longer when the first neon comes on ,untill the neon on the cap comes on but its best to stop the charge when the first neon comes on for the sake of the capacitor so you know ya not over chargeing it to much with this cap charger , now for the power it puts into the caps or current well i use my split diode hydrogen oxygen electrolysisi to test it instead of the fingers , this time chargeing the cap up and dumping the charge into the electrolysis thing dosent make the orange glow and fiz, like the other cap charger dose but you still get the bang when ya short cap out but if i short cap out after trying it on the split diode electrolysis exsperiment the charge is gone so even if the thing dosent glow orange and fiz, the charge is still going somewhere so ill try it in the day when i can see it better Quote Link to comment Share on other sites More sharing options...
audioguru Posted November 13, 2005 Report Share Posted November 13, 2005 Hi Steven,It looks good.An NE-2 neon light bulb begins to light with 70V to 90V across it. An NE-2H is a little brighter and needs 90V to 110V. Perhaps you should add an 80V zener diode in series with it so that you will have a more accurate indication that a capacitor is nearly fully charged. ;D Quote Link to comment Share on other sites More sharing options...
steven Posted November 14, 2005 Author Report Share Posted November 14, 2005 :)thankyou audio guru ill try that as soon as i find out if i can get that zener as i think 75 volts is the highest you can get here at the nearest electronics store Quote Link to comment Share on other sites More sharing options...
steven Posted November 14, 2005 Author Report Share Posted November 14, 2005 :)anyone planing on biulding this ignition coil version cap charger i just found out it , that the positive output puts out arcs to ya finger to but somehow when i hook up a capacitor to it it charges up great with no damage yet as if the cap has an internal resistance of its own Quote Link to comment Share on other sites More sharing options...
steven Posted December 17, 2005 Author Report Share Posted December 17, 2005 heres a printed circuit board for the high voltage flyback driver circuit for the next high voltage capacitor charger, i just have to wire up the pots and the timer which runs to the main board from the timer socket board Quote Link to comment Share on other sites More sharing options...
steven Posted January 30, 2006 Author Report Share Posted January 30, 2006 the latest high voltage capacitor charger under construction is an ignition coil version includeing the capacitor thats 4700uf 250vdc and an scr fireing circuit so when its charged the light will come on then with the push of a button the charge will be dumped iether into my mini coilgun or other but untill its finsished ill add pictures here of a relay circuit im working on to be used in a high voltage capacitor charger so all you would have to do is push a button and it will switch on the chargeing circuit for the capacitor for a certain amount of time , pending on where you have the rotary pot switched to , now the circuit i collected and made into a printed circuit board version is basically an off after delay relay circuit , and the circuit runs off a nine volts battery temporarilly and the relay is actually 12 volts and works ok in the circuit so latter ill use a supply voltage 9 volts from a regulater circuit and bleed the input from the main 12 volts lead acid cell battery to power the circuit for the relay timeing etc etc now the voltage devider i used here has a 1m resister and 3x 1.8m resisters and ive tapped between all then aftyer the 1m resister which runs back to the 1m pot and with the 1m pot turned down i timed each response of the relay to each position i switch the rotary pot to and if i use the 1m pot it adds more time to each resister the pot is switched to , im not to good at technicle exsplanationsss but this is the best i can do now i tested this by runing a wire from a 12 volts lead acid cell battery , to a large 12 volts electric moter, and the positive from the battery to one of the relay contacts then from the other relay contact to the moter positive then switched the relay timer to say the position that keeps the motor going for say 5 seconds till its timeing cycle is up then the moter switches off, now this circuit will be used to switch on the high voltage cap charger for any time i choose then switch it off after the time has ended so the cap will get say 60 seconds or more or less pending on where i switched the pot to then after say 60 seconds of chargeing the relay will switch it off by isolateing the positive wire to the whole high voltage cap charger . on the resister devider board ive got little decals with the times in seconds on them for each switch of the rotary pot and that dosent include the extra seconds i get when i adjust the main 1m pot. i did time each test with my watch so i have all the details Quote Link to comment Share on other sites More sharing options...
steven Posted January 30, 2006 Author Report Share Posted January 30, 2006 :)the 2 diodes allready on the board are only 1n4148 diodes and so ill still add a rectifier diode to the relay inputs for the reverse voltage protection Quote Link to comment Share on other sites More sharing options...
steven Posted January 30, 2006 Author Report Share Posted January 30, 2006 :) Quote Link to comment Share on other sites More sharing options...
steven Posted January 30, 2006 Author Report Share Posted January 30, 2006 :)by the use of the 1m potentiometer i get an extra 15 seconds of capacitor chargeing before the time runs out and the relay turns off the whole circuit. if i set it for 50 seconds chargeing and set the pot to full i get 65 seconds of chargeing. without this circuit you may be able to modify it to turn off when the chargeing neon comes on , by use of a light deactivated relay circuit , once my tests are completed ill redesign the latter ignnition coil version cap charger on printed circuit board with the extra features , thats includeing the 9 volts regulater to power the timer relay circuit and the ignition coil driver all on the one board Quote Link to comment Share on other sites More sharing options...
audioguru Posted January 30, 2006 Report Share Posted January 30, 2006 Hi Steven,You have made a very nice high voltage system. ;DDid you know that a 555 timer doesn't need a regulated supply? Its max is 18V so it will work from a 12V supply exactly the same as it works from 9V. Post the timer's schematic again to see if its output resistor needs to be changed with the 3 extra volts. What voltage rating is the relay's coil and what is its resistance? Quote Link to comment Share on other sites More sharing options...
steven Posted January 31, 2006 Author Report Share Posted January 31, 2006 thankyou audio guru ill get to it as soon as can be , just got out of bed the relay is 12 volts ill have to measure its resistance and the resisters well the pot is 1m and the first resister after that is 1m and the last 3 resisters are 1.8m each so all these timeing resisters are on the long board Quote Link to comment Share on other sites More sharing options...
steven Posted January 31, 2006 Author Report Share Posted January 31, 2006 :)the 12 volts relay coil has a 240 ohms resistance and its 12 volts, ill add the circuit soon as i have to get off line for half an hour Quote Link to comment Share on other sites More sharing options...
steven Posted January 31, 2006 Author Report Share Posted January 31, 2006 here is the circuit that i biult this from and it dosent include the , resister devider and any modifications but if you study it right by the pictures and details ive given you can get it right Quote Link to comment Share on other sites More sharing options...
steven Posted January 31, 2006 Author Report Share Posted January 31, 2006 :)the capacitor from pin 5 on the ic is a 0.01uf ceramic or 104 mono block and the electro the the left is 10uf Quote Link to comment Share on other sites More sharing options...
audioguru Posted January 31, 2006 Report Share Posted January 31, 2006 Hi Steven,I'm glad that your relay's coil is 240 ohms instead of the 40 ohms like before. I'm also glad the the 555 has a 12V supply instead of only 9V with a regulator or battery.I suggest that you use a 1N4001 or 1N4002 diode in series between the 555's output and the relay's coil for a lower voltage loss than the 1N4148.You are lucky that the relay works. Its minimum operating voltage is 9V. The 555's output has a typical voltage loss of 1.5V (2.2V max) and the 1N4148 has a typical (and max) voltage loss of 1V. Therefore if the relay and 555 were at their worst but still guaranteed specs, the relay won't work. Quote Link to comment Share on other sites More sharing options...
steven Posted January 31, 2006 Author Report Share Posted January 31, 2006 thankyou for the reply audio guru ive put a diode across the relay inputs for protection before , anyhow as i upgrade the circuit ill add any new ideas you may forward to the topic Quote Link to comment Share on other sites More sharing options...
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