just finished this zenlight. I used surplus heating elements instead of lamps. They are 240volt/1500watt, and are all close to 32 ohms. I am using two in parallel per device. I built the amp based on fig. 16 in the article.
The mosfets are irfpb250's, my rail is 47 volts at full power, but I am using a variac, and am running at 25 volts as the sinks are a little small.
The amp sound fantastic with my lowthers, but I am using it now for some 10" o.d. by 5.5' el-pipos.
I need a better crossover, does anyone know of a project for balanced in/out 2-way active crossover?
The mosfets are irfpb250's, my rail is 47 volts at full power, but I am using a variac, and am running at 25 volts as the sinks are a little small.
The amp sound fantastic with my lowthers, but I am using it now for some 10" o.d. by 5.5' el-pipos.
I need a better crossover, does anyone know of a project for balanced in/out 2-way active crossover?
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
It does not glow. the elements were designed for 240 volts/1500 watts, and at full power in my amp, they see 47 volts. at full power they radiate alot of heat, but not as much as the heatsinks. I run it at 25 volt rails, and the elements do not even break a sweat (almost cold!), and the heat sinks will allow me to touch them briefly.
I put 120 ac across one element for test and it got red hot.
I did not expect them to glow from the beginning, and in my application each device has the equivalent of a 3000 watt 16 ohm resistor. I had to parallel the elements to increase the bias, which insured me that the elements would not glow.
If I had bigger sinks, I could run it at full power and have a space heater with very appealing sonic attributes.
I put 120 ac across one element for test and it got red hot.
I did not expect them to glow from the beginning, and in my application each device has the equivalent of a 3000 watt 16 ohm resistor. I had to parallel the elements to increase the bias, which insured me that the elements would not glow.
If I had bigger sinks, I could run it at full power and have a space heater with very appealing sonic attributes.
Great work Coils
I thought there might be some interest in the results of tests I've done in this light (could not resist saying that). Actually, I've been into inductor loading lately but, along the way, I measured the available bulbs and even a heater element from the local Home Depot. All data is recorded manually after a few seconds of stabilization. Results could be different over u-seconds or mili-seconds such as audio frequencies. Notice that the only measured device that exhibits almost pure resistive qualities is the heater element. If you would like the whole .xls file send me a PM...
I thought there might be some interest in the results of tests I've done in this light (could not resist saying that). Actually, I've been into inductor loading lately but, along the way, I measured the available bulbs and even a heater element from the local Home Depot. All data is recorded manually after a few seconds of stabilization. Results could be different over u-seconds or mili-seconds such as audio frequencies. Notice that the only measured device that exhibits almost pure resistive qualities is the heater element. If you would like the whole .xls file send me a PM...
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