Advanced relay?
Printed From: the12volt.com
Forum Name: Relays
Forum Discription: Relay Diagrams, SPDT Relays, SPST Relays, DPDT Relays, Latching Relays, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=81428
Printed Date: July 03, 2025 at 11:16 AM
Topic: Advanced relay?
Posted By: debeerd
Subject: Advanced relay?
Date Posted: August 10, 2006 at 4:33 AM
Does anyone here know how to use the IRFP460 in a circuit ?
Replies:
Posted By: KPierson
Date Posted: August 10, 2006 at 8:54 AM
That part isn't an 'advanced relay' it is a fairly standard mosfet. What exactly are you trying to do with it? Mosfets, much like standard bjt transistors, can be used in a wide variety of applications. ------------- Kevin Pierson
Posted By: debeerd
Date Posted: August 10, 2006 at 11:08 AM
Oh, I didn't know that... I'm using it to change a 5v trigger to 12v trigger. G - 5v trigger D - 12V in and also out S - Ground using a 10K resistor over G & S Will try to post a pic of what I'm doing.
Posted By: debeerd
Date Posted: August 10, 2006 at 11:29 AM
Posted By: KPierson
Date Posted: August 10, 2006 at 12:24 PM
Your picture won't work, as you are using the same pin for 12vin and 12vout. That will leave you with 12vdc at all times. Instead of having 12vdc on the middle pin that pin will provide a (-) output. You can use that negative output to then drive a P channel mosfet to output 12vdc. Again, depending on what you are trying to do (switching speed, switching frequency, output current) it's hard to give you advice on how to proceed. If you merely want to change a 5vdc output to a 12vdc output I would recomend the use of a reed relay, no resistors, good reliability, small size, no need to bias anything. ------------- Kevin Pierson
Posted By: debeerd
Date Posted: August 10, 2006 at 3:53 PM
That is what I'm not understanding, the circuit I copied it from works.... It is used to up the pulses from the fuel management system to the standard rev counter. The 5v output is to little to excite the rev counter. This circuit makes the pulses stronger, or so it looks, but it does work...
Posted By: debeerd
Date Posted: August 10, 2006 at 4:15 PM
I'm going to see if I can get my hands on it again to test it again... 
Posted By: KPierson
Date Posted: August 10, 2006 at 4:17 PM
You arn't using the exact same circuit. The one you copied takes a 5vdc input and turns it in to a (-) output that can be used in a 12vdc system. There is a resistor use to pull the output up to 12vdc to provide a postive reference voltage on the output. You basically need to emiminate the 12vdc feed and use the 12vdc output as a (-) output that can be used to drive a relay or whatever you need it to do. ------------- Kevin Pierson
Posted By: KPierson
Date Posted: August 10, 2006 at 4:23 PM
OK, that last post gives me some idea of what is going on here. A relay wouldn't be a good choice, as your switching too fast, too often. On your input/output you need to include a 10K resistor. Wire one end to the mosfet and the other end to your 12vdc input. Now, tie your output directly to the pin on the mosfet and go from there. This will provide you a +12 reference when the input is grounded and a +0vdc reference when the input is 5vdc (backwards from the original signal, but it should carry the same info. ------------- Kevin Pierson
Posted By: debeerd
Date Posted: August 11, 2006 at 4:11 AM
Posted By: KPierson
Date Posted: August 11, 2006 at 7:33 AM
You need the other one as well to make sure that the input is fully 'off' when no signal is applied. So, two 10K resistors and you should be set. You can add a few more resistors for protection (limit current) but they aren't absolutely necesarry. ------------- Kevin Pierson
Posted By: debeerd
Date Posted: August 11, 2006 at 10:49 AM
I made it like the last diagram, without the resistor over G & S. It works without the earth wire ??
Posted By: debeerd
Date Posted: August 14, 2006 at 3:41 PM
This works on my Opel Corsa, but not on an Opel Kadett ?? My coil is positive triggered and the Kadett is negative trigger, could this be the problem ??
Posted By: KPierson
Date Posted: August 14, 2006 at 4:35 PM
Without an o'scope it would be hard to figure out exactly what the problem is. ------------- Kevin Pierson
Posted By: debeerd
Date Posted: September 02, 2006 at 5:02 AM
Can this circuit be made to give a negative pulse or positive pulse ?
Posted By: KPierson
Date Posted: September 02, 2006 at 9:25 AM
You can output either one, based on the type of transistor you use. An N channel will give you a (-) pulse, a P channel will give you a (+) pulse. Of course you'll have to wire the P channel up slightly differently to get the (+) pulse, but you'll basically just switch the grounds with the positives.
------------- Kevin Pierson
Posted By: debeerd
Date Posted: September 02, 2006 at 3:44 PM
How would I know if it is a N or P ?
Posted By: KPierson
Date Posted: September 02, 2006 at 4:07 PM
By the part number of the device.
------------- Kevin Pierson
Posted By: debeerd
Date Posted: September 03, 2006 at 3:46 AM
All it says is IRFP460 445XD
Posted By: KPierson
Date Posted: September 03, 2006 at 9:54 AM
Google says: 500V Single N-Channel HEXFET Power MOSFET ------------- Kevin Pierson
Posted By: debeerd
Date Posted: September 05, 2006 at 3:21 PM
Ok, so I can generate - pulses only ?
Posted By: KPierson
Date Posted: September 05, 2006 at 10:09 PM
Yes, with that part number it is designed to switch the (-).
------------- Kevin Pierson
Posted By: debeerd
Date Posted: September 09, 2006 at 7:53 AM
Ok, cool. Which one is needed then to do + switching ?
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