Re: [Repeater-Builder] Cooling fan relay circuit?

2007-05-17 Thread Per Molund

The ELK-960 Delay Timer should fit rigth in, however no
temperature sensing.

http://www.elkproducts.com/products/elk-960.htm

---per
LA9XKA


At 05:05 17.05.2007, you wrote:
My club has several ACC controllers and none have provided for cooling
fan control.  Does anyone have a simple circuit to turn on a fan with
PTT and then keep it running for xx minutes after PTT is released?
The repeater PTT line goes to ground on transmit.

Most of the NE555 timer circuits that I have seen will not work in
this configuration.  Delay on drop out.  DODO.  Thanks de David K5RAV






Yahoo! Groups Links







Re: [Repeater-Builder] Cooling fan relay circuit?

2007-05-17 Thread [EMAIL PROTECTED]
Hi Guys.
I have used these in the past.
This kit is from OZ but I am sure you must be able to get something 
similar over there.
 http://www.jaycarelectronics.com/productView.asp?ID=KC5381CATID=keywords=KC%25

Chow for now
Brett

Per Molund wrote:
 
 
 
 The ELK-960 Delay Timer should fit rigth in, however no
 temperature sensing.
 
 http://www.elkproducts.com/products/elk-960.htm 
 http://www.elkproducts.com/products/elk-960.htm
 
 ---per
 LA9XKA
 
 At 05:05 17.05.2007, you wrote:
  My club has several ACC controllers and none have provided for cooling
  fan control. Does anyone have a simple circuit to turn on a fan with
  PTT and then keep it running for xx minutes after PTT is released?
  The repeater PTT line goes to ground on transmit.
  
  Most of the NE555 timer circuits that I have seen will not work in
  this configuration. Delay on drop out. DODO. Thanks de David K5RAV
  
  
  
  
  
  
  Yahoo! Groups Links
  
  
  
 
 


[Repeater-Builder] Cooling fan relay circuit?

2007-05-16 Thread drwoolweaver
My club has several ACC controllers and none have provided for cooling
fan control.  Does anyone have a simple circuit to turn on a fan with
PTT and then keep it running for xx minutes after PTT is released? 
The repeater PTT line goes to ground on transmit.  

Most of the NE555 timer circuits that I have seen will not work in
this configuration.  Delay on drop out.  DODO.  Thanks de David K5RAV



RE: [Repeater-Builder] Cooling fan relay circuit?

2007-05-16 Thread Eric Lemmon
David,

It's not necessary to run the fan unless the radio gets hot.  The most
reliable and practical method of controlling a fan is also the simplest and
cheapest: a snap-action thermo-switch mounted on a heatsink fin.  I use a
Cantherm switch from Digi-Key that starts the fan at about 120 degrees
Fahrenheit.  It's a good idea to select a DC-operated fan that is specified
for low EMI, such as those made by Panasonic.  Some DC fans generate a lot
of conducted and radiated noise.

73, Eric Lemmon WB6FLY
 

-Original Message-
From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of drwoolweaver
Sent: Wednesday, May 16, 2007 8:05 PM
To: Repeater-Builder@yahoogroups.com
Subject: [Repeater-Builder] Cooling fan relay circuit?

My club has several ACC controllers and none have provided for cooling
fan control. Does anyone have a simple circuit to turn on a fan with
PTT and then keep it running for xx minutes after PTT is released? 
The repeater PTT line goes to ground on transmit. 

Most of the NE555 timer circuits that I have seen will not work in
this configuration. Delay on drop out. DODO. Thanks de David K5RAV