[ARC5] [External Sender] solid state vibrator basics

[J Mcvey]

 I stared at that circuit a while trying to figure it out. I think the trick is that the transformer core is driven into saturation and when the field collapses, the reverse  pulse will turn the transistor off . The oscillation is basically set by the L-R time constant.
However , it may be prone to latch-up, ( it is probably better if the two resistors are NOT equal) and it  drives the transformer pretty hard producing heat losses.
The bipolar transistors also have a saturation voltage which robs a little amplitude from the transformer while also generating more heat.
Gotta give it kudos for simplicity, though!
Jim

    On Tuesday, February 9, 2021, 10:17:29 AM EST, Bill Henderson <bill.henderson at ocdsb.ca> wrote:  
 
 Please see attached for another approach
 - Bill H. / va3hwa



 
|      |  Sender notified by 
 Mailtrack 02/09/21, 10:15:28 AM  |   |

 
On Mon, Feb 8, 2021 at 7:29 PM J Mcvey via ARC5 <arc5 at mailman.qth.net> wrote:

This not specific for your vibrator, but the concept works for any of them, you just have to wire to the correct pins for your particular type.
The synchronous contacts ( if any) are replaced by rectifier diodes ( in the correct polarity , of coarse).
The oscillating frequency is approx 110 Hz
I used BUZ11 mosfets with good results.
The zeners can all be adjusted to 12V , since the mos gates are good to 20V and the 4047 is 18v max.


______________________________________________________________
ARC5 mailing list
Home: http://mailman.qth.net/mailman/listinfo/arc5
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:ARC5 at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: https://www.qsl.net/donate.html

CONFIDENTIALITY NOTICE:  The information transmitted in this e-mail is intended only for the person to whom it is addressed and may contain confidential, personal and/or privileged material.  Any distribution, use or copying of this e-mail or the information it contains by anyone other than the intended recipient(s) is unauthorized.  If you are not the intended recipient and have received this communication in error, please notify the sender immediately and delete the message and any attachments from your system.  
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/arc5/attachments/20210209/5481d72e/attachment-0001.html>