Dear all,
I am currently building a driver for a Stax Lambda Pro before I start work on my own electrostatic headphone. the first version will be built to low cost, a later version may be more Super HiFi. The headphones come from ebay are in beutiful condition but I assume they are working fine, I dont know yet and getting something working (and cheaply) tested is the first objective.
This is the first installment. It would have the title "Voltage doublers, how many stages?"
I am basing the voltage doubler / "ladder", on the stax circuit. ""high-quality-stax-headphone-adapter""
Now I just happen to have lots (8 unused) torroidal 230 V -> 2X22 V transformers from a bargin ebay buy, but they do look rather old and the sticky tape sealing then is loosing its sticky but they are not so bad as to need electrical tape. I thought I might play with these to drive the headphones in the short term. I suspect I will apresiate the knowledge gained.
So I thought to save my unused transformers I would build more stages on the voltage doubler and run the system off 44 V AC, well the doubler is less and less a doubler with distance from the supply. Tomorrow I will set up a second transformer effectively making a over built 1:1 transformer so will have 240V, and in series making 88V driving it though I suspect if I was buying transformers for the job I might want 100V like the original circuit as my estimates suggest the numbers would be right on the money for voltages. Some times it good to simulate in reality, much as I should learn how to do this on the computer.
Like the Circuit I attached, I used 0.1 uF capacitors (650 and 1000V) and 1000V diodes, but I guess each stage only sees the magnitude of the AC signal sent to the ladder so lower ratings woudl have been fine? I found little benefit after the first 6 diodes. The 7th doubler brings me to about 276V and the 8th makes no benefit at all.
I assume the reduction in effectiveness of the voltage doublers is due to the capacitors smoothing the AC more and more over time, does this mean the frequency of the voltage doubler / "ladder" would be very limited in maximum frequency of operation making frequencies like 1 Mhz out of practicality? Or possibly due to leakage in my breadboard (at such low voltages I hope not, but it was super cheap)
I see Quad uses 8 diodes in its power supply and a 10th of the size of the capacitors, used by Stax, so knowing Quad amplifiers and how they optimise for performance/cost I assume all 8 provide a benefit, so I doubt my experience with 6 stages being the limit to voltage doublers being practical / cost effective. I assume the same frequancy of supply (50Hz) with much lower capacitance's and closer to ideal diodes would improve the stages efficiency in driving an ideal unleaking speaker.
All thoughts apresiated as I am nearly completely self taught in electronics and have a reasonable skill in maths.
I am currently building a driver for a Stax Lambda Pro before I start work on my own electrostatic headphone. the first version will be built to low cost, a later version may be more Super HiFi. The headphones come from ebay are in beutiful condition but I assume they are working fine, I dont know yet and getting something working (and cheaply) tested is the first objective.
This is the first installment. It would have the title "Voltage doublers, how many stages?"
I am basing the voltage doubler / "ladder", on the stax circuit. ""high-quality-stax-headphone-adapter""
Now I just happen to have lots (8 unused) torroidal 230 V -> 2X22 V transformers from a bargin ebay buy, but they do look rather old and the sticky tape sealing then is loosing its sticky but they are not so bad as to need electrical tape. I thought I might play with these to drive the headphones in the short term. I suspect I will apresiate the knowledge gained.
So I thought to save my unused transformers I would build more stages on the voltage doubler and run the system off 44 V AC, well the doubler is less and less a doubler with distance from the supply. Tomorrow I will set up a second transformer effectively making a over built 1:1 transformer so will have 240V, and in series making 88V driving it though I suspect if I was buying transformers for the job I might want 100V like the original circuit as my estimates suggest the numbers would be right on the money for voltages. Some times it good to simulate in reality, much as I should learn how to do this on the computer.
Like the Circuit I attached, I used 0.1 uF capacitors (650 and 1000V) and 1000V diodes, but I guess each stage only sees the magnitude of the AC signal sent to the ladder so lower ratings woudl have been fine? I found little benefit after the first 6 diodes. The 7th doubler brings me to about 276V and the 8th makes no benefit at all.
I assume the reduction in effectiveness of the voltage doublers is due to the capacitors smoothing the AC more and more over time, does this mean the frequency of the voltage doubler / "ladder" would be very limited in maximum frequency of operation making frequencies like 1 Mhz out of practicality? Or possibly due to leakage in my breadboard (at such low voltages I hope not, but it was super cheap)
I see Quad uses 8 diodes in its power supply and a 10th of the size of the capacitors, used by Stax, so knowing Quad amplifiers and how they optimise for performance/cost I assume all 8 provide a benefit, so I doubt my experience with 6 stages being the limit to voltage doublers being practical / cost effective. I assume the same frequancy of supply (50Hz) with much lower capacitance's and closer to ideal diodes would improve the stages efficiency in driving an ideal unleaking speaker.
All thoughts apresiated as I am nearly completely self taught in electronics and have a reasonable skill in maths.