Power conditioner for the FT817 power pole adapter

The popular 3D printed (EBAY) power pole adapter for the FT817 is augmented with 7 layers of power conditioning & protection.

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Add on this ready made 1.5" square PCB in a few minutes to the 3D printed power pole adapter available on EBAY for complete FT 817 transceiver power protections including transients, reverse polarity, over current, surge current, thermal shutdown and brown out handling. The conditioner features all SMT construction with semiconductor voltage ref. and current sensing under closed loop control for an auto reset protection response time that is 50x as fast as a fast blow fuse or a PTC. Bonus 10% thermal loading reduction on the FT817 internal power supply!
NO SMT work is required if you purchase the item from my EBAY sale. Just 2 #24 wires to attach and a couple holes to drill. Order direct from

Look at the 16 file image sequence below, they are all commented.

Just orient the red and black poles to your preference when assembling, they are easy to switch around.

Theory of operation ,EAGLECAD Files and LTspice schematic simulation :

Feature by Feature functional delivery technique & EAGLECAD Files

1) Rev polarity protection s handled by a PFET  Drain to Source conduction for minimal voltage drop.

2) Transient suppression is  done by a 16V TVS with a 5A fuse for extreme transients

3) Power shutdown for surge current, continuous excess current and  power dip under load is controlled by a biased op amp using an LED for a voltage ref. and the Rdson of the output  PFET for current sensing.

4) Thermal shutdown is triggered by the positive tempco of the Rdson of the PFET.

5) Noise suppression is done by a pair of 10nF ceramic caps with high voltage ratings to prevent capacitance degradation

6) Decoupling is via a larger 4.7 uF ceramic cap to reduce ripple and mitigate wring inductance.

7) Transient current draw support is enabled by slowing the gate response of the final PFET, but not so much as to compromise the fast shutdown upon over current.

Installation is simple as the circuit is inserted into the positive pole line to the plug and grounded via the existing FT817 power pole adapter  ground screw.

Note that at full TX load the conditioner's MOSFETs will be too hot touch as they unload the FT817 of 10% of heat dissipation making for longer transceiver life. So, don't burn your fingers. Ensure proper ventilation for the conditioner when transmitting.


Document with all assembly Pics for easy printing.

document - 5.24 MB - 01/25/2020 at 20:12



JPEG Image - 717.69 kB - 11/10/2017 at 03:53


Drill PP gap.jpg

JPEG Image - 1.14 MB - 11/10/2017 at 03:52


PP hole aligns with PCB solder ball.jpg

JPEG Image - 679.18 kB - 11/10/2017 at 03:52


Adapter separated.jpg

JPEG Image - 602.98 kB - 11/10/2017 at 03:53


View all 17 files

  • 1 × Assembled item on EBAY , item #132393671077
  • 1 × Note the LTspice schematic for a DIY BOM

View project log

  • 1
    How to install the PCB

    Well, this is simple; follow the image sequence supplied as all images are commented. Be sure to enjoy your new power conditioned Power pole 3D printed adapter!

View all instructions

Enjoy this project?



brb2n8 wrote 02/26/2020 at 17:54 point

I ordered a PCB on eBay. Unfortunately it does not work. It always burns the red LED.

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