References: <1245872871.20180101103858@gmail.com> <2B728BD9A22E47E991B5DABA279D0D27@Clemens0811> <188CDC35293448D088ABCA3CCC6B2184@Clemens0811> <831993214.20180101112620@gmail.com> <43E1315F9F0541D9965B368BDEA5F943@Clemens0811>
From: Mal Hamilton <g3kevmal@talktalk.net>
In-Reply-To: <43E1315F9F0541D9965B368BDEA5F943@Clemens0811>
Message-Id: <5C7B5B7E-E9E7-4F5F-8115-F543EE2649EA@talktalk.net>
Date: Mon, 1 Jan 2018 14:05:23 +0000
To: rsgb_lf_group@blacksheep.org
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Subject: Re: LF: RE: RE: Si5351A syntehsiser able to fire a FET driver chip directly??
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Most hi power FET s I have used need around 10V in class D or E amps
I.e. driver sq wave V
Dr.  Chip Tc 4426 or equivalent

G3KEV


> On 1 Jan 2018, at 12:07, Clemens Paul <cpaul@gmx.net> wrote:
> 

> Thanks Clemens, I'd need two, correct? Could I try say 4 to 16 turns
> on two FT-37-43 cores, which I have? 

A turns ratio of 4:16 gives a 1:4 voltage ratio so this ratio would require only one core.

One could make one 1:4 (V) transformer or two cascaded 1:2 (V) ones,
the latter probably being more feasible.
But 4 turns for the primary on a FT37-43 give 4µH which is only 3.4 Ohms on 137kHz.
This would probably eat up all the "ooomph" of the driver chip by the magnetizing current.
I would suggest at least 500µH which is 430 Ohms on 137kHz.
So you'd have to choose a different material,e.g. "J".
With two cascaded FT 37-J's this would require 15 turns for the primary and 30 for the secondary
which appears just manageable.
A bigger core would make things easier,though.
Then you could use one core with 15:60 turns.

73
Clemens
DL4RAJ 


ill the Si synthesizer chip have
> enough "ooomph" to drive them?

> -----Original Message-----
> From: owner-rsgb_lf_group@blacksheep.org 
> [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Chris Wilson
> Sent: Monday, January 1, 2018 12:26 PM
> To: Clemens Paul
> Cc: dead.fets@gmail.com
> Subject: Re: LF: RE: RE: Si5351A syntehsiser able to fire a 
> FET driver chip directly??
> 
> 
> 
> Hello Clemens,
> 
> Monday, January 1, 2018, 11:10:44 AM, you wrote:
> 
>>> How about a 1:4 transformer? ->Voltage ratio!
> 
> 
> Thanks Clemens, I'd need two, correct? Could I try say 4 to 16 turns
> on two FT-37-43 cores, which I have? Will the Si synthesizer chip have
> enough "ooomph" to drive them?
> 
> 
> 
> 
> -- 
> Best regards,
> Chris                            mailto:dead.fets@gmail.com
> 
> 
> 
> ---
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