and by the way....regarding the problems you pointed out:
Sure the pcb is not isolated but it is possibile to obtain a DC tension without a transformer as long as the current absorbed is small. The pcb uses reactive capacitance to create the DC current.
the IDEC RU2S-A220 suggested for the build and visibile in the photographs is a relay driven with 220v.
The IDEC Ru2s-D24 is the second relay suggested and both offer interesting features such as a built in LED, a test function and are best mounted using a specific socket which helps in case of failures.
In regards to the NTC thermistors. I honestly don't seen a problem. IF two NTC 10D-20 are adequate for inrush currents to the toroid then what might happen with 2 groups in parallel would be for either one or the other to drop resistance and channel the surge current (thus leaving one group non functional given the resistance differential). If continuity across one branch is lost then the second would work as a failsafe.
If you see anything wrong with all of this please tell me.
Sure the pcb is not isolated but it is possibile to obtain a DC tension without a transformer as long as the current absorbed is small. The pcb uses reactive capacitance to create the DC current.
the IDEC RU2S-A220 suggested for the build and visibile in the photographs is a relay driven with 220v.
The IDEC Ru2s-D24 is the second relay suggested and both offer interesting features such as a built in LED, a test function and are best mounted using a specific socket which helps in case of failures.
In regards to the NTC thermistors. I honestly don't seen a problem. IF two NTC 10D-20 are adequate for inrush currents to the toroid then what might happen with 2 groups in parallel would be for either one or the other to drop resistance and channel the surge current (thus leaving one group non functional given the resistance differential). If continuity across one branch is lost then the second would work as a failsafe.
If you see anything wrong with all of this please tell me.
Last edited:
That's VERY unsafe. So unsafe that we have only ONE rule regarding technical censorship on this forum: NO direct mains-powered circuits. Use an isolation transformer and make sure that your chassis is tightly connected to earth ground. Otherwise, you're risking your own life and that of innocent family, friends, and kids who could get electrocuted from a simple fault that (in a safe build) would blow fuses.
Use an isolation transformer and make sure that your chassis is tightly connected to earth ground. Otherwise, you're risking your own life and that of innocent family, friends, and kids who could get electrocuted from a simple fault that (in a safe build) would blow fuses.
I understand....then please delete my posts
Use an isolation transformer and make sure that your chassis is tightly connected to earth ground. Otherwise, you're risking your own life and that of innocent family, friends, and kids who could get electrocuted from a simple fault that (in a safe build) would blow fuses.
Yes! ... So unsafe that insurance companies have been able to block payments for fire liability, in many states ... If you burn your own house down, insurance companies may not be obligated to pay. If you burn your apartment building down, you could go to jail and be liable for all of the damage and injury.
teflon hand made speaker cables, cable from navships ?
Yes, Teflon-insulated UPOCC copper or silver, Neotec-brand conductors in a 4-braid. Bass/MR cable is 2 pairs of 18g. copper; MR/treble cable is a pair of that copper plus a pair of 23g. silver. I terminated it with Audioquest's direct-silver-over-copper spades, large and small for the amp and V'steen 5As. Have also added a 72VDC dielectric-bias system ala Audioquest.
What do you mean by 'cable from navships'? What's a navship?
No please don't. I have removed the original schematic because it represents an unacceptable safety hazard and violates forum policy.Also please note that this is very OT for this thread, this thread is reserved for photographs of solid state amplifier projects.
Banned
Joined 2002
navships | eBay
nav ships is the seller on ebay.. he sells teflon wire, one off's on runs from ship wiring harnesses that they can't splice and use. I buy lots of silver wire from him, really good wire too..
I am confused! Soft start circuitry unsafe?
Soft start circuitry HAS to connect directly to the AC input (after the on-off switch) and then directly to the toroid transformer for it to work. Why would you need an isolation transformer? I usually use an AC light bulb after the on-off switch. Is that unsafe too? Please explain, I need the education.
Soft start circuitry HAS to connect directly to the AC input (after the on-off switch) and then directly to the toroid transformer for it to work. Why would you need an isolation transformer? I usually use an AC light bulb after the on-off switch. Is that unsafe too? Please explain, I need the education.
While having not seen the published schematic, your proposition seems valid, softstart boards use to work on live mains.
this one is properly designed and yet still carries this Warning.
Every builder who incorporates this properly designed pcb, into their equipment, must ensure that they do so in a safe manner.
Users and others must not be put at risk by incompetent builders.
Last edited:
Soft Start Circuit
Now that we have established that soft start circuit has to be between the mains and the torroidal transformer can we please have the soft circuit diagram re-posted or a corrected version re-posted? I was interested in studying it but it got yanked before I could see it!
Now that we have established that soft start circuit has to be between the mains and the torroidal transformer can we please have the soft circuit diagram re-posted or a corrected version re-posted? I was interested in studying it but it got yanked before I could see it!
Shall someone share the schematic to show HOW NOT TO DO IT? I wonder if I may be following wrongly regular procedure when designing power supply stages.