With the voltage too high, the ballast resistor is too low to cause extinction. The lamp will "simmer" in the sustain region, hence the low glow. True, I believe you can have any voltage, but you must limit the current. Think of it this way, the capacitor is the energy storage for the main flash. The lamp just needs an ignition pulse, much like a xenon lamp. * | __O Thomas C. Sefranek WA1RHP@ARRL.NET |_-\<,_ Amateur Radio Operator: WA1RHP (*)/ (*) Bicycle mobile on 145.41MHz PL74.4 ARRL Instructor, Technical Specialist, VE Contact. http://hamradio.cmcorp.com/inventory/Inventory.html http://www.harvardrepeater.org -----Original Message----- From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf Of David VanHorn Sent: Friday, September 28, 2007 12:43 AM To: Microcontroller discussion list - Public. Subject: Re: [EE] Neon lamps On 9/27/07, Thomas C. Sefranek wrote: > Voltage is too high! > Google the ignition voltage of NE-2s. How would it ever get too high? The ckt is cap in parallel with the neon, and there's a 10 or 22 MEG resistor between the cap/neon and the battery. Voltage ramps up to about 55-60V, then dumps down. But when they get in this half-on mode, they sit there with 55-60V on them. Hard to measure, the scope probe capacitance affects things. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist