user TURBO?s replication of Steven Mark?s TPU ?

[CTG Labs]

Rob Hi,

Yes, I am UK based, 10 miles from London Bridge, where are you?

I have just a DPST toggle to switch between two caps for a couple of ranges.  Could do with a more refined design as well.

So, if you are able to give a circuit for this, that would be great for me and the others.

Someone emailed me about finding the ICL8038.  They are discontinuned but cricklewood electronics still had a load.  As for anywhere else, people are just going to have to search.  The MAX038 would be better, but I cannot find those, they go up to 20Mhz with all waveforms.

The ICL8038 design could also include the sine and triangle outputs and you could use a split voltage power supply circuit too to get proper AC out, so we can mix waveforms.

Have you easy access to PCB etching equipment?  I dont normally make PCBs because its all experimental or I build it on strip board, so I have to go round a mates to use it.  If you design one and are etching one, perhaps you could etch me one too and I can send you a tenna or something.



Regards,

Dave.

[CTG Labs]

Rob,

Perhaps the TL494 design would be better since the ICL8038 is no longer made and many people wont be able to find it, but the TL494 is not that old and still produced.  I have a couple here as free samples from Texas Instrument, etc.

What is the top frequency?


Thanks,

D.

[CTG Labs]

By the way, I recommend people use valve circuits if possible since SM has said that it worked with valve circuits, then they replaced them with of the shelf solid state generators and it wouldnt produce the effect.  So there can be some special condition that is required and it took a long time to get this out of a SS design.

However, I am seeing some effects with SS, but there is no way to no just yet if it is the right thing, or the same thing as in the SM tpu or a different effect!

So, those who have experience with valve circuit, I recommend you try those.  Those that do not, I recommend you play with some lower voltage solid state circuits instead because the voltages from tube power supplys will kill you if you dont play nicely...


D.

[SPP-48]

Hi folks
This is my virgin posting so be gentle?
I have no formal training in electronics but am a tinkerer and decided to spend my time on something worthwhile like helping to save the planet.
I have spent my evenings and weekends the last few months tinkering with magnets and electromagnetic devices, and in particular using tones in conjunction with various coil/core configurations. After reading all the postings on this topic I have decided to have a go with this device.
I?ve built a couple of cheap tone generators but can?t get them to work properly. I?ve had more success using a freeware program called NCH tone generator through my PC sound card. It works well and seems to produce nice clean sine waves. I was thinking that for testing purposes I could use 3 PC?s each running the tone generator software through the soundcard into the device. Testing for OU would be difficult, but it could quickly nail the frequencies required. Any comments would be appreciated.

Cheers

S

[CTG Labs]

Hi,

This could be an expensive way of doing it and you will be limited on your top frequency because of the sound card.

You may be better off fixing your tone generators.

Also, once the mix is found, the effect is not that dramatic, once it is found, it needs to be fed back in a loop and then it takes off!


D.