petrev
Flashlight Enthusiast
Hi
An FET Switch for reduced resistance and higher current use without damage to switch parts.
Did this once before but didn't take any guide pics ! so here is a Simple-FET-Switch How To . . .
Circuit by JimmyM [opens in New Window]
First Cut a 30mm Disc from 2 Sided Copper PCB - I used 32mm hole saw
Mark it up + These are most of the tools and parts I used
(little DPAK is for reference - Used the bigger D2PAK F2804L for upto 40V)
4.7K Resistor only for Voltages ~>20+V
(JimmyM suggests a switch to 2.2k and 5k for the IRF2804 MOSFET - it will switch faster and thus reduce the heat generated during turn on and off)
Alternative MOSFETs are the 24V 1324 (?24V Ref) or if voltage won't exceed 30V the IRLR7843 (Ref.JimmyM)
or >40V with IRF3206
Dremel off the rough edges of the disk to fit and chamfer the edges so that there are no unwanted contacts.
Use the KIU-Base as a guide to drill through the mounting holes
Dremel off the rough edges round all the holes and make the hole for the Batt-Neg wire to go to the back side.
Cut the grooves to form a rudimentary circuit . . . I used the small engraving tool in the Dremel.
Prepare the surface with some Emery Paper/Wet and Dry Sandpaper/Or Similar
Mark the Through Hole position for the Source FET leg
Drilled and then cleared a non contact area on the circuit side using the engraving tool
Solder all the parts in place . . .
1. First tin the contact area for the Drain HeatSink. Then place FET in position with the Source Leg folded back through the hole and solder Drain HS.
2. Then the Gate leg is soldered down.
3. Then solder the G-S resistor in place on the Source leg
4. Then solder the G-S resistor to the Gate Pad/Area
5. Then solder the (+20Vonly) Switch-Gate resistor to the Gate Pad/Area
6. Then solder Sw-G resistor to the SW Pad/Area
Attach the Red Switch Wire (Front)
and the Brown/Black Batt-Neg Wire (Rear) and solder Source leg to back.
.
Stuff it into your KIU-Base and feed the KIU-Socket wires through the central hole
I attached some temporary pins to the Batt Neg and KIU-Pos wires, then temp. soldered the Drain-KIU wire and tested using a 3x C-Lion Mag-KIU.
I always wire my KIU-Sockets with the NEG to the Pin-Socket near the Logo and then fill the Logo in Black to remind me !
Plug together then touch the SW-Wire to the POS and :thumbsup: all OK.
That's it ! ! !
All you have to do then is fit it into a KIU modified D-Switch as before.
Assemble into D-Mag . . .
Done
Pete
An FET Switch for reduced resistance and higher current use without damage to switch parts.
Did this once before but didn't take any guide pics ! so here is a Simple-FET-Switch How To . . .
Circuit by JimmyM [opens in New Window]
First Cut a 30mm Disc from 2 Sided Copper PCB - I used 32mm hole saw
Mark it up + These are most of the tools and parts I used
(little DPAK is for reference - Used the bigger D2PAK F2804L for upto 40V)
4.7K Resistor only for Voltages ~>20+V
(JimmyM suggests a switch to 2.2k and 5k for the IRF2804 MOSFET - it will switch faster and thus reduce the heat generated during turn on and off)
Alternative MOSFETs are the 24V 1324 (?24V Ref) or if voltage won't exceed 30V the IRLR7843 (Ref.JimmyM)
or >40V with IRF3206
Dremel off the rough edges of the disk to fit and chamfer the edges so that there are no unwanted contacts.
Use the KIU-Base as a guide to drill through the mounting holes
Dremel off the rough edges round all the holes and make the hole for the Batt-Neg wire to go to the back side.
Cut the grooves to form a rudimentary circuit . . . I used the small engraving tool in the Dremel.
Prepare the surface with some Emery Paper/Wet and Dry Sandpaper/Or Similar
Mark the Through Hole position for the Source FET leg
Drilled and then cleared a non contact area on the circuit side using the engraving tool
Solder all the parts in place . . .
1. First tin the contact area for the Drain HeatSink. Then place FET in position with the Source Leg folded back through the hole and solder Drain HS.
2. Then the Gate leg is soldered down.
3. Then solder the G-S resistor in place on the Source leg
4. Then solder the G-S resistor to the Gate Pad/Area
5. Then solder the (+20Vonly) Switch-Gate resistor to the Gate Pad/Area
6. Then solder Sw-G resistor to the SW Pad/Area
Attach the Red Switch Wire (Front)
and the Brown/Black Batt-Neg Wire (Rear) and solder Source leg to back.
.
Stuff it into your KIU-Base and feed the KIU-Socket wires through the central hole
I attached some temporary pins to the Batt Neg and KIU-Pos wires, then temp. soldered the Drain-KIU wire and tested using a 3x C-Lion Mag-KIU.
I always wire my KIU-Sockets with the NEG to the Pin-Socket near the Logo and then fill the Logo in Black to remind me !
Plug together then touch the SW-Wire to the POS and :thumbsup: all OK.
That's it ! ! !
All you have to do then is fit it into a KIU modified D-Switch as before.
Assemble into D-Mag . . .
Done
Pete
Last edited: