Variable Frequency Drive PCB File Release.

Thank you Mr. Paul

LoSaYa

I have the same unit, yes 22 volt motor. Paul did mention in an earlier post the secondary is 28 volt. 160 volt primary, 28 volt secondary

Jason Myszka

@Samuel, @Eddy: Without further info we can only guess at the transformer, I'm afraid. If I'm not totally confused, Paul is applying a 160V square wave to the transformer, which is about 113 Vrms. He is applying that between the 260 V tap (an unusual primary voltage?) and the 100 V tap, so where normally 160 Vrms would be. The output of the transformer therefore should be about 70% of the voltage it would normally be. The induction motor has 22V (rms?) on its label, if I read that correctly. If 70% of the normal secondary output is 22Vrms, the normal secondary output is roughly 30 Vrms. The "8" and the "12" are just pin numbers of the transformer, I think. It probably has 7 pins on the primary side (common and 6 different primary voltages possible) and 5 pins (pins 8 to 12) on the secondary side (for common and 4 secondary voltages, probably two pairs of positive/negative). So my guess would be that it is a transformer with universal primary taps (including the strange 260V tap) and a 30 VAC secondary (or equivalently two 15 VAC secondaries in series). Take my guess with a grain of salt since I'm not experienced with power supply design! I could easily be off by a factor of two.

Edwin Steiner

Does having 3 5v Zener diodes in series for the protection circuit make it 15v?

Daniel Wells

Hi Mr Carlson, I'm confused also about the transformer. Would you provide more specifics on the Transformer you used. What is the expected voltages on the input and output of the transformer.

Eddy Bass

I’m confused about the transformer. Your diagram shows two wires in and two out but the schematic shows one 260v tap and one 100v tap. Wouldn’t there be 4 connections? Exiting one says 8 and one 12. What is 8 and 12? So confused.

Samuel Taylor

What's an isolated ground?

Ty Jay

I found a excellent resource for shielding material. I buy those frozen microwave chicken pot pies. Inside the box the top area is coated with a material that absorbs the microwaves and browns your crust on the pie. I cut out that material, use spray adhesive to stick it inside my project box or tube. It works really really well and the meal isn't bad either:)

Emerald Pawn

In a previous life, when I was reverse engineering "electronic things," there was one engineer that ribbed me about that as well.... He had lived in Japan too. (I have to even out the Solder pronunciation :^)

Mr Carlson's Lab

Mr Carlson, I know that you are very particular about details, so I will just let you know that it is pronounced "hack-ko" rather than "hey-ko." Source: I lived in Japan for three years. ;-)

Bruce Dow

When I looked at the schematic, I noted 6 (RHI) and Pin 8 (Ref Adjust) is tied together with pin 6 floating. Did you mean to tie pins 6 and 7 together and ground pin 8 as in the example on figure 22?

Bill Hall

I was going over the schematic last night and looking at the datasheet for the LM3914 and noted on figure 22 a close resemblance to the actual layout of the circuit used. The difference is pins 6 (RHI) and 7 (Ref out) are tied to the base of the pnp transistor and Pin 8 (Ref Adjust) is tied to ground. From my evaluation of the chip based on the block diagram on page 8 of the data sheet, pin 6 is an input to the + side of the op amp drivers and pin 7 is a voltage output from an internal reference source. Pin 8 (Ref Adjust is tied direcctly to ground in the block diagram which means it cannot be a driving voltage output.

Bill Hall

Hello Mr. Carlson! Thank you for sharing your knowledge. I wonder how high the oscillator frequency could go. I am interested in building this VFD to run 115 VAC, 3 A, 400Hz motors. I probably would have to have a different output transformer value and do you think the components at pin 5 and 6 on the TL494 would allow me to adjust the frequency up to 400Hz? Or I would need to change the values of the resistors and the capacitor? I guess that there’s a formula to calculate the values knowing the frequency value desired. Could you comment on that please? Thanks in advance Lewis.

Lewis Muzzio

I would love to build a single to three phase VFD using some inexpensive dedicated ic packages, that would be a very practical circuit for home machine shops and cnc diy projects

benjmain vines

Disregard the question above please. You answered it in the video.

Radio Amp Doctors

Great project!! Why the 3 4uf caps in parallel? Is that to achieve the odd 12uf value?

Radio Amp Doctors

Hi Lowell. The transformer in this VFD application is part of the circuit. If the transformer is not there, the motor would see square waves. this would be due to the lack of inductance and capacitive filtering.

Mr Carlson's Lab

Hi Mr. Carlson, if I am using the VFD for a 120V motor on 120v mains, is the transformer necessary, assuming the motor is fused? I am new to switching circuits (and no longer fear them in the slightest - thanks to your videos!)

CIRCLOTRON

Thank You Michael!

Mr Carlson's Lab

Mr. Carlson, I am so impressed that I have doubled my pledge. I am learning so much from just watching. Thank You!

Michael Lynch

Hi Scott. 20mA is some pretty small Current. The VFD's job is to change operating frequency so Induction motors can have variable speed. If your using a DC motor, changing the pulse width would be all you would need for a speed controller (at a set frequency)

Mr Carlson's Lab

Hi Mike. The 4 resistors is to supply the needed current to power the IC and switching circuitry. The more resistors you have in parallel, the more current supplied. This is because the total resistance drops. The Zeners are in series to double the regulation Voltage, IE: 2X5.6 = 11.2V. Depending on the load, this will vary a little. Heating is also a drift factor. On the main page, listed under the reward levels, are the ways I communicate here. Just click on overview at the top of the page, and search the perks of the different levels. Happy New Year!

Mr Carlson's Lab

Will not let me comment sometimes. In the drawing why did you put 4 resistors at the 5.6 v zener area. Heat? Also what is the best way to ask questions or contact you? hager111@aol.com Thanks for these classes.

Mike Hansen

I am about to automate my HVAC with a control and have 0-10vdc or 4 to 20ma output on the control, I want to use as an input on a VFD to my fan motor. I want to build my VFD and like your VFD for the solder vac and would like to incorporate it into my project. I am just now getting back into electronics after many years absence thanks to you. You do tend to inspire. What would be a good way to do this and what would I have to beef up to compensate for the higher amperage fan motor of my air handler?

scott palmer

Hi Song. If you were to simply unplug the motor, you would have all your connections for the external drive. So with the motor unplugged in the Hakko, you now have the power leads, and the leads that run to the motor. The leads that originally powered the motor, go to the trigger circuit in the drive. This is why there is rectification before the opto, as the original power for the motor is AC. The open leads to the motor are now connected to the drive output transformer. So really, the drive is placed in line between the original power leads and motor. This makes the jumper plug an easy connection, as it just connects the motor back to it's original source. Merry Christmas Song!

Mr Carlson's Lab

Hi Mr. Carlson. Merry Christmas! Can you share some about the wiring in Hakko side? From the video, I can tell you need 2 wires out from Hakko which is the trigger signal. And antoher 2 wires feed into Hakko to drive the pump using 90Hz 28V AC power signal generated by your controller module. So I was wondering how did you separate the power supply for the pump and iron in Hakko, and which wire you've pick up to send the trigger signal to the controller module? I just got a used Hakko 484 in hand. According to the specs, it's very similar with 470 in terms of the pump. The overall difference could be on the power consumption of soldering iron.

Kai Song

LOL, Hi Richard. This project was built years ago, and I had no intention of sharing this. I do prefer using SM components (and others do here as well) as it almost eliminates drilling. Drilling is a bigger pain than SM components by a long shot. Many projects you find here are thru-hole style....But I can almost guarantee, once you build something surface mount, you won't go back. Cleaner, smaller, little to no drilling.... so on.

Mr Carlson's Lab

Arrggh!!!! Please don't use surface mount components! I am old school- through lead only, and do not have the eyes or the equipment to do SMC. Do you use the SMC because of availability or lack of for through hole components? Seems like a big PIA to handle these tiny parts, why bother, if you don't have to?

Richard Marshall

Thanks Andre, Merry Christmas and a happy New Year to you and yours as well! I'm not sure of the Aoyue 474 build topology. Whats the motor Voltage, and is it an AC induction motor? The Hakko mod to the plug is really easy. The original motor leads go to the opto "trigger" circuit in the drive. This now leaves the motor unhooked. The leads that run back to the Hakko from the drive connect to the motor. So the leads that originally sent the current to the motor in the Hakko now only power the opto to turn the drive on. This allows just a simple jumper plug to return everything to normal.

Mr Carlson's Lab

Hi Pete. The Taps used on the transformer primary are the 100 and 260 Volt Taps, which leaves 160V between them. The secondary taps are at 28 Volts, and the motor is rated 22V AC. This slight "Over Voltage" helps with getting it moving fast (quicker vacuum at the tip) The motor seems fine with it.

Mr Carlson's Lab

Hi JP. I'm not sure of the Aoyue 968A build topology. If it has an AC induction motor (no brushes) it may work. The motor in the Hakko 470 is actually 22V AC. There are a few different versions of the Hakko, some with DC motors as well. I'm glad you're enjoying the video's. Merry Christmas to you and yours as well!

Mr Carlson's Lab

Hi Mr. Carson's Lab! Thank you for what you do. I have learned a lot through your videos in the last couple of years on YouTube. I was wondering if this will work as-is when I connect the Aoyue 968A+ which I have modded to use with a desoldering gun with the vacuum air suction functionality. Thanks in advance and have a Merry Christmas.

JP

Another really interesting approach to a common kind of problem when it comes to desoldering machines. Mine would really benefit...Thanks Mr Carlson's Lab! I just have a small question ( played the video a couple times but still flummoxed ) the actual transformer being switched by the MOSFET is what primary/secondary voltage? Perhaps it was a recovered unit? Mains where i live is 230Vac so i certainly need to consider the fullwave rectified potential available.

Pete Bronlund

Thanks Mr. C for this interesting Video. I understand the frequency Drive and how it works, but can you explain how you connected the Hakko to the drive? What I mean is how and what wires you disconnected from the Hakko to connect the Drive. The reason I asked for this is I have a Aoyue 474A++ that I would like to try this on. Thanks again and Have a holy and bless Christmas and 2018 to you and you family.

Andre Gopee

Oh come on, you can't be serious.

Mr Carlson's Lab

Glad you're back Ian!

Mr Carlson's Lab

Thanks for your kind comment John! I'm happy to share.

Mr Carlson's Lab

Glad to assist Jim, Merry Christmas right back!

Mr Carlson's Lab

Thanks Psient! Merry Christmas to you (and yours) too!

Mr Carlson's Lab

The taps on the transformer that are connected are the 100V tap, and the 260V tap. This gives 160V worth of winding's between the taps.

Mr Carlson's Lab

Merry Christmas to you too Chase!

Mr Carlson's Lab

LOL!

Mr Carlson's Lab

yes i quit aswell in protest but as soon as they saw sense rejoined, cannot be without my Mr Carlson fix, Happy Christmas.

Ian Taylor

"Very high signal to noise" is a very apt description John. Paul always leaves me with 'lots to chew on' and soon applications for things I thought were not particularly interesting begin present themselves. Merry Christmas and Happy New Year to Paul and to all who are striving to learn the art of applied electronics.

Jim Edmondson

like WOW!!! Before I subscribed/enrolled, I could not even remotely follow your discussion of a schematic. That has definitely changed. You have generated (a pun) a learning community with one hand tied behind your back given the recent kerfuffle. This student erupts in ebullient applause (4-yeah), four your analysis and efforts in practical progressive lessons, of course!! Thanks and good holidays to you sir.

Psient

The primary is the 260v tap, right?

Carlos Cabrera

Very awesome! Drives are my job and so this is a very exciting post for me. Thanks for all your great videos and have a merry Christmas!

CaptainJinx

Very useful circuit and great explanation as well! Thanks Paul, for sharing this with us! I opened up the schematic first before I watched the video. Had a funny moment at the morning as I asked myself for a second: What is an "ISK Switch x4"? -> <a href="https://giphy.com/explore/facepalm/" rel="nofollow noopener" target="_blank">https://giphy.com/explore/facepalm/</a> myself :D

Reb Elba

Your teaching is as meticulous as your bench work—very high signal/noise ratio! Thank you for sharing at this level of quality.

John Weld

Ann C

Thanks Rod! Merry Christmas to you and yours as well.

Mr Carlson's Lab

Happy Christmas Paul - Hoping you have a better year in 2018

Rod Smallwood

You're very welcome Phil!

Mr Carlson's Lab

Thank you so much for sharing with us, Paul! Very neat device and easy to customize

Phil