Quiet EL wire inverter, based on a boost converter and a H bridge driver IC. Provides 360Vpp drive at 1.2kHz, up to 3M of typical wire. Device plugs into a USB port or wall plug.
The circuit has a basic boost converter controlled by a PIC10F204, that has a comparator and a voltage reference. The EL is driven by a microchip HV809, set to run at about 1.2kHz.
This is the third revision of the design, the first was based on a HV859/HV860. This basically functioned well, but the light output was way too low due to the lower voltage boost converter built into them. The second revision was based on a discrete device boost converter, (a oscillator, comparator, a AND gate, and a HV809). The second version had more light output, but still the boost converter was not able to reach 180V, got stuck at about 150V. to improve that this latest version uses a PIC to control the boost converter, this allowed a easily variable frequency/duty cycle. I also changed the switch and inductor.
I built 5 of these PCBs, using a 100uH inductor. 3/5 PCBs flickered. I found that the uProcessor was being reset intermittently due to the fast transients in the boost converter. The cross talk made it to the uProc's power supply line and caused it to reset. I fixed it by adding a bypass capacitor on the backside of the programmer pin head array. I also turned down the H-Bridge frequency to reduce the power loss. It now works with no flickering and no hot devices. I have had on a moon in my sons room for a month now with no issues.
I have received a revision to the latest design, the FET was getting a bit hot when trying to drive a meter of EL wire. So I added some metal to the layout to try to reduce the temp on it. The temperature of the FET was too hot to keep my finger on it for more than 30 seconds. I have built one it does work, and I am trying to optimize the Boost converter signal period on duty cycle to get the most power output while keeping the FETs temperature under control.