Which PT for Overtone Special?

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Kassie
Posts: 117
Joined: Tue Aug 24, 2010 3:00 pm
Location: The Netherlands

Some more pictures.

Post by Kassie »

Transformers got in.. still waiting on the backordered Power Transformer. It is sent today.. came all the way from the great plains in Texas, to Nashville, to Paris, to Roden (Netherlands), pronto on my chassis. Gosh I wish I could have trafelled with them and see those great plains for myself. All for free.. thanks Mouser.

[IMG:800:600]http://i932.photobucket.com/albums/ad16 ... C02289.jpg[/img]

OT secundary goes under the trafo through an extra drilled hole as per dumble.
[IMG:800:600]http://i932.photobucket.com/albums/ad16 ... C02288.jpg[/img]


Choke en OT primary/centertap.
[IMG:800:600]http://i932.photobucket.com/albums/ad16 ... C02285.jpg[/img]

Internal trafo for the relay power.
[IMG:800:600]http://i932.photobucket.com/albums/ad16 ... C02277.jpg[/img]

Internal wiring of the OT secondary towards the impedance selector.

[IMG:600:800]http://i932.photobucket.com/albums/ad16 ... C02281.jpg[/img]

Internal wiring of the OT primary/centertap, and the choke.

[IMG:800:600]http://i932.photobucket.com/albums/ad16 ... C02282.jpg[/img]

[IMG:800:600]http://i932.photobucket.com/albums/ad16 ... C02279.jpg[/img]

There were a lot of holes next to eachother in the Ceriatone Chassis. And I had to drill/file some extra to make it all fit. As a result the chassis weakened. So I decided to use extra wide and firm mounting rings to add back some firmness to the chassis.

[IMG:800:600]http://i932.photobucket.com/albums/ad16 ... C02284.jpg[/img]

Question: Do I need to connect the relay filament transformer secondary centertap to ground? Is that necessary when it gets converted to DC anyhow?
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Structo
Posts: 15446
Joined: Wed Oct 17, 2007 1:01 am
Location: Oregon

Re: Which PT for Overtone Special?

Post by Structo »

It depends what type of rectifier you use on the relay supply.

Full wave or fullwave bridge.
Tom

Don't let that smoke out!
Kassie
Posts: 117
Joined: Tue Aug 24, 2010 3:00 pm
Location: The Netherlands

Re: Which PT for Overtone Special?

Post by Kassie »

Structo wrote:It depends what type of rectifier you use on the relay supply.

Full wave or fullwave bridge.
It's the stock ceriatone.. with 2 diodes.. So I guess it's a full wave rectifier.. so I guess it indeed needs the centertap connected to ground?
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ToneMerc
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Joined: Sun Apr 26, 2009 3:55 pm
Location: East Coast

Re: Which PT for Overtone Special?

Post by ToneMerc »

Kassie wrote:
Structo wrote:It depends what type of rectifier you use on the relay supply.

Full wave or fullwave bridge.
It's the stock ceriatone.. with 2 diodes.. So I guess it's a full wave rectifier.. so I guess it indeed needs the centertap connected to ground?
It's a doubler, no centertap unless you like smoke.

TM
Kassie
Posts: 117
Joined: Tue Aug 24, 2010 3:00 pm
Location: The Netherlands

Re: Which PT for Overtone Special?

Post by Kassie »

ToneMerc wrote:
Kassie wrote:
Structo wrote:It depends what type of rectifier you use on the relay supply.

Full wave or fullwave bridge.
It's the stock ceriatone.. with 2 diodes.. So I guess it's a full wave rectifier.. so I guess it indeed needs the centertap connected to ground?
It's a doubler, no centertap unless you like smoke.

TM
Thanks! I was wondering about those extra diodes at the relays themselves. I am going to study some more material about the bridge rectifiers.. good learning experience.
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ToneMerc
Posts: 3480
Joined: Sun Apr 26, 2009 3:55 pm
Location: East Coast

Re: Which PT for Overtone Special?

Post by ToneMerc »

Kassie wrote: I was wondering about those extra diodes at the relays themselves..
Quicker to point you to Google than type out an explanattion.

http://www.physics.unlv.edu/~bill/PHYS483/relay.pdf

TM
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