Small, compact VFD

Hi,

Your musical instrument look very cute. your only problem is, it is designed to works in 110 V 60 Hz ( probably 110 V assume) and your power supply is 230V 50 HZ and you have a 230 / 110 V step down transformer. If you can get an inverter with input 230V 50 Hz and out put 110 v 60 Hz your problem get solved . If one with 60 Hz is not readily available in the local market you can buy an inverter (and modify the inverter transformer & LC circuit values to get 60 Hz out put,if the output is not 60 Hz). Other meted is to use a 50 HZ to 60 Hz converter. ( convert your 110v 50 Hz supply to 110 V 60 Hz as you have already got 230/ 110 50 Hz transformer with your instrument).

Please see the Link below.

http://www.50hz.com/electroc.html?gclid=COqz_M7T65ICFRrCbwodwSag5Q

The problem is that over the frequency conversion the instrument should be tunable so the converters frequency should be set (about from 48 to 62 Hz) and the frequency should be fairly stabile. The power consumption of the starter asynchronous and the operational synchronous motor together is about 20 Watt. I can see my sad future, I will have to build a converter...

Hi,

If you can get hold of the inverter given in the link bellow along with a AC to DC converter (230 V , 50 HZ to 24 Volts DC rectifier unit readily available off the shelf). It will serve the purpose.

http://193.173.58.150/details_sine.asp?Id=14

Only check the wave form before purchasing also the powerr capacity of uniit to drive the motor

Thanks, but that is a fixed frequency inverter. The only way for tuning a Hammond is changing the rotation speed of tone wheels connected directly to the synchronous driver motor.

So this is what, like a Hammond B3? And how dare you think about tuning it!!! All other instruments should take their key from the Hammond B3, Hee Hee!

It's a C3 and it should be played together with a normal pipe organ. I think it's easier tuning the Hammond than tuning thousands of pipes... :-)

Now that's an interesting reply!

The B3 (and C3) are thought of as made to be played in a combo. R&B, Jazz, and Rock; with the organ being one of the solo instruments. Why do you say it was meant to be played aginst a pipe organ?

Oh! And can I date your sister?

My sister is married :-)

The Hammond's owner is a Hungarian artist, Laszlo Fassang.

http://www.fassang.com/main.php?locale=en

He bought it about half a year ago. Besides the well-known baroque and classical pieces he often plays jazz-improvisations and plans to give a concert with a Hammond - pipe organ duo.

What! Dee-Dee can't be married!!! She's too young, unless you belong to the FLDS!!!!

That organ may have C3 insides, but the case is for a C2 or earlier. The decorative woodwork with the crosses was done away with on the C3.

The C3 was also the only "C" model to have percussion.

You are right about needing to change the power supply frequency to change the tuning of the organ. The advantage is, that the pitches of all tones will change proportionally with changes in the tone generator's rotational speed.

At one time, the factory offered a tone generator motor with gearing to play the correct pitch when supplied with 50 Hz power. This was mainly for the export market, although at that time there were still a few areas of the US with a 50 Hz electric supply.

I worked as a serviceman for a local Hammond Organ studio forty-eight years ago. One of the selling points of this instrument was, that it was built to last. The photograph gives evidence that this one has survived pretty well. I wish all of you a continued long and successful career.

Tone generator motor... How did that work? Most of the organs I was exposed to used electronic oscillators to generate the sound. Was this a different system?

I've almost forgotten to answer: Hammond is a very unique electro-mechanical instrument. http://en.wikipedia.org/wiki/Hammond_organ

Thanks!

Here's a Wikipedia article on the Hammond organ. It includes a brief section on the electromechanical tone generator.

http://en.wikipedia.org/wiki/Hammond_organ

Because the generator was driven by a synchronous motor, the instrument would never go out of tune, so long as it was powered by AC of the correct frequency. This was a selling point, because the vacuum tube oscillators used as tone generators in early electronic organs required frequent re-tuning.

When the Hammond organ was introduced in 1935, some areas in the US were supplied with 50 Hz power. The company provided a different motor assembly which would drive the tone wheels in the tone generator at the proper speed. If the owner moved to a location where the line frequency was different, the motor assembly would have to be changed to keep the organ in tune.

Thank you for your post.

This a a C3 and it already has percussion. The instrument is in a very good condition. One of the keys were broken but we ordered a replacement via internet and swapped it. In addition there was a bad soldering in the volume control but that was all.

The original reverb unit is missing and somebody built a spring-type reverb into the box of the Leslie. We have to do something with it because it's almost unusable due to the acoustic feedback.

I would be delighted if we could talk about the problem out of this thread,

my mail address is qqberci dot samunet dot hu

A Model Number would help. Can not determine the type of tone generator. This WEB page will help you though. www.mitatechs.com/organcom.html

Apologies if you've already done this:-

http://www.google.hu/search?hl=hu&q=60+Hz+inverter&btnG=Google+keres%C3%A9s&meta=cr%3DcountryHU

I've already done it but what I need is a tunable inverter. I can see my dark future I will have to work... I variable frequency inverter with a PLL frequency control will be the right solution. I had hoped someone else solved similar problem...

I know that you don't want to change much, but would not an AC to DC conversion be a good idea with a DC motor with very exact electronic speed control, with feedback, be a possible way out?

We don't want to change anything on the original instrument otherwise it will not be a genuine Hammond...

"We don't want to change anything on the original instrument otherwise it will not be a genuine Hammond..."

Seems to me that you have two possibilites that I have not seen mentioned. The first is to search e-Bay and other sources for one of the 50 Hz motors that other posts have described. They are probably rare, though. There may be an online discussion group devoted to Hammond organs and restoration, maintenance, etc, and that's where I'd start; if anyone knows of a source of parts, they should.

Second, while it departs slightly from the spirit of your intention, is it possible to do the change mechanically? Could you, for example, add a 5:6 timing belt or gear drive to speed up the tone wheels when driven by a motor running at 5/6ths of its required speed? I've done similar things, using existing holes and features to add a jackshaft or similar, and leaving the device able to be returned to original condition and method of operation. This would also mean that if you locate on of the 50 Hz motors later, you could swap it in without harm.

One of the most important points would be the tunability and almost impossible to do it mechanically (and it would change the original organ)

According to the technical articles and information from Bubbapebi in post 24, the Hammond CANNOT be tuned, nor can it get out of tune:

"Here's a Wikipedia article on the Hammond organ. It includes a brief section on the electromechanical tone generator.

http://en.wikipedia.org/wiki/Hammond_organ

Because the generator was driven by a synchronous motor, the instrument would never go out of tune, so long as it was powered by AC of the correct frequency."

Because you are synchonized to 50 Hz instead of 60, the notes are at EXACTLY 5/6ths of their intended frequency; you can easily obtain gearing or timing belts that will provide an EXACT 6:5 ratio, making the tonewheel speeds precisely correct. This also means that the tones are precisely correct again - we're talking to several decimal points here, if the 50 Hz power grid is controlled properly. (and the Hammond clock company was partly responsible for getting 60Hz under control in the USA! Yes, that same Laurens Hammond) A mechanical solution of this sort is mathematically precise, as good as the best electronic one possible, and vastly cheaper. It is almost certainly easier to do, but needs to be done by someone who fully understands the reasons for maintaining the originality, and who can design the adaptation to utilize existing mounting points and so forth. If the drive is not already direct (one article mentions gearing to the tonewheels!), it is likely that only a pair of pulleys and a belt, a pair of gears, or similar, would need to be swapped - and the old ones would be set aside awaiting re-installation if your friend ever locates an original 50Hz Hammond motor. It is possible that a planetary gearset could be added in-line, with the motor mounted upon spacers.

Try talking with the best mechanical engineer you know, and with some local machine shop people - there is almost certainly someone nearby who understands what I'm saying and can show you how to do it without harming the Hammond. Wish I were a few thousand miles closer . . .

It has also been clarified that Hammond can be tuned by shifting the supply frequency of the tone wheel motor... It comes from the principle of sound generation.

One thing that you can try, I have done this before is, use a single phase VFD of the proper size for the load, and use the output to feed a step down transformer. In this case 230vac to 115vac. With some inverters you can use two legs of the output with no problem. On others you will have to load all 3 phases using two transformers.

The problem is not the voltage, we have a single phase synchronous motor and we have to control accurately the rotation speed.

Thats what the VFD is for. The transformer is used as an interface between the VFD and motor, one to reduce voltage if needed, the other to attenuate the carrier frequency.

I would consider eliminating the transformer modification to restore the original condition of the organ and adding an external Variable Frequency Drive. ABB makes some very fine drives in the fractional horse power range. http://www.state-electric.com/abb-variable-frequency-drives/index.htm?gclid=CNzMmLOK75ICFRZciAod4ij9AA

You can package the transformer with the VFD or eliminate the transformer by doubling the hp rating of the VFD. Since your organ probably has a single phase motor and most VFDs are three-phase, one-third of the output will not be used. The drive can be programmed to operate at a preset speed and ignore the output imbalance.

Thank you, it seems to be a good solution. The smallest one, ACS50 would be suitable for the organ