Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

sensitive and powerful PC to transmitter keyer

Status
Not open for further replies.

neazoi

Advanced Member level 5
Joined
Jan 5, 2008
Messages
3,753
Helped
13
Reputation
26
Reaction score
9
Trophy points
1,318
Location
Greece
Activity points
34,264
Hi, I want to see how simple a keyer can be made, sensitive enough to be driven by the audio of the PC sound card, but powerful enough to switch power into a 300-500mA 12v requiring CW transmitter.
My goal is to have the least discrete components possible, I do not mind if they are SCRs of custom-wound toroids or small commercial audio transformers.
The circuit to key is this https://qrp.gr/easy40/index.htm and I do not mind about "key clicks" in this simple circuit.
 

barry

Advanced Member level 5
Joined
Mar 31, 2005
Messages
5,180
Helped
1,118
Reputation
2,248
Reaction score
1,123
Trophy points
1,393
Location
California, USA
Activity points
28,355
I would use a P-Channel MOSFET with the gate driven by an NPN (I'm too lazy to draw a schematic, but I will if you don't get what I mean). Your pc output drives the NPN base; the NPN collector is tied to the MOSFET gate.

Can you get a DC level out of your sound card? If not, you'll have to have some kind of filter on that signal.
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top