Simple turbo pump controller

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chad ramey
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Re: Simple turbo pump controller

Post by chad ramey »

Thanks, I'll go ahead and order one from lesker. Have you been able to test your's yet?
richnormand
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Re: Simple turbo pump controller

Post by richnormand »

Not really. Got it to turn with a two-phase sine signal from my audio generator into a 100W strereo amplifier as a quick test after downloading the specs sheet. I got the vacuum chamber and coupling from e-bay during the summer. Already have the backup pump. Now waiting for some SS hoses and two KF25 valves. All the stuff is in a box at this time. The "honey-do" list takes priority..... Please post cost and ## for the ring once you find it.
Cheers and thanks.
chad ramey
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Re: Simple turbo pump controller

Post by chad ramey »

Thanks for the information. Sounds promising, I wish you the best of luck with getting it running. I have full intentions of having mine running on my reactor by the third weekend of september (hopefully earlier than thst).

I have the ISO63 centering rings on several sites:
Lesker-
http://www.lesker.com/newweb/flanges/ha ... fm?pgid=al
$26.00
LDS Vacuum Shopper-
http://vacuumshopper.stores.yahoo.net/lfalcenrinwv.html
$20.00
MDC-
http://www.mdcvacuum.com/urd/uniface.ur ... ay?1.a.1.m
$29.00

I'm going to talk to a friend at Quintronix tomorrow to see if they have any available, and if they do I'll let you know.

-Chad
DSchultz
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Re: Simple turbo pump controller

Post by DSchultz »

I found a surplus source for the RFP2N08L FETs. I need to buy 20 of them to make the minimum order. Does anybody else need these FETs or have you all found some other FET that works as well without being un-obtanium?

I am going through Amphenol and ITT Cannon catalogs to try to identify the power connector. No Luck so far.
richnormand
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Re: Simple turbo pump controller

Post by richnormand »

Hi Dan.

You might be interested at the NTE line of substitutes. They list the NTE2382 as a replacement for both the RFP2N08 and the RFP2N10.... The specs are identical except for a 100V rating instead of 80. I ordered 5 NTE2382 from Allied Electronics ( $3.95 CAD each) since they were in stock. No min orders either. They have been working for almost one month and no issues. The NTE line is very popular for all sorts of repairs and it has a very extensive range of "equivalent" components. Most local electronics repair stores will carry them but they are slightly more expensive than ordering the exact part (if still available) from the large outfits such as Mouser, Allied, Digikey and such.

I initially replaced the 555 with a phase locked loop for smoother transitions and went back to the original 555 as there were no real improvement. I did add a switched selection of both full speed and standby (60%), each with its own 10 turn pot. Also for about $12 on eBay I got a small four-digit display frequency module. This gives me the rotational speed, 1500 Hz full and 900Hz standby. I can now follow the pump in ramp up or down to a full stop.

For power a 24V OEM surplus supply can be internally (mis)adjusted to provide the 28V. I included a separate switch for that too. This allows keeping the 5V to the logic electronics during ramp down. The motor back emf at full speed will heat the MOSFETs too much unless you keep the 5V alive to keep switching (with the 28V off).

Finally I noticed that in very rare cases the pump will not start and one FET is full on and the other full off. Not a good scenario. A small twist of the pump or a restart will cure that. I guess the rotor can stop in a no-man-land position. The freq display solves that issue since I can immediately see the startup upon switching the 28V on. If it stays static it is just a matter of turning it off and reset the 5V and then the 28V.

As far as the connector is concerned I ended up soldering a wire to each pin and fan them to a strip junction block with a label for each function. Nice that the full specs for the pump are available online too.

By the way I am not using the fan that came with the pumps either. They both barely get warm after several hours of running. Maybe if I flow lots of gas through them.... but that is for later.

EDIT: See note by Alexi further down in the posts about the difference between the RFP2N08 and the RFP2N08L. The NTE sub does work well for me however.
DSchultz
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Re: Simple turbo pump controller

Post by DSchultz »

I had a negative experience several years ago with a NTE "universal replacement" FET which was not so equivalent. Since then I try to find the original part whenever possible. I have too many projects going than to try to re-engineer what others have already proven to work.

What are you using for a power connector? Do you just push the wires onto the pins one at a time?

Dan
richnormand
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Re: Simple turbo pump controller

Post by richnormand »

I agree with you Dan,

Note that I used "equivalent" in quotation (as with a big grain of salt) as YMMV but for this applications they seem to work for me and others may find the NTEs easier to obtain than chasing the exact part. Been using the substitutes for more than 30 years now from the time they were RCA SK series, Sylvania ECG subs and now NTE and, yes, you need some creative empathy from time to time as they are not the real McCoy. Initially made for people fixing TVs and such at the time.

I always try to find the exact match when possible too. However a friend of mine that is in the electronic component failure analysis and counterfeit or rebranded detection business has a mitigated opinion about getting components from non-authorized dealers, in particular resellers of older parts no longer available. What you see may not be what you think you have. Not much of an issue here but not funny in medical, aerospace or other safety related applications. That being said, I have used resellers of obsolete or hard-to--get components several times with great success. It all depends on the price and minimum order. Or... how desperate I was to get the part vs redesigning the whole mess with modern components!

For the connector I simply tinned the end of the wires and tinned each individual pin on the pump connector. Laid the two side by side and I then wetted each together one by one and heatshrinked each and then the lot together with an RTV silicone core. Dont overheat as I did not check how the wires are attached to the pins inside the pump body. Quite sturdy and easy to dismantle when or if I manage to find the mating connector at a decent price. I have two other pumps as spares. Did not want to invest much money until I got a feel. I will next change the oil wick but these look like they were an excellent deal.

Cheers
gpecke
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Re: Simple turbo pump controller

Post by gpecke »

Dear Alexi,

Thank you very much for your post. I have bought two pumps on the strength of your information.

I am glad you mentioned the fine black muck, which needed very careful removal.

I have already bought two Alcatel/Adixen MDP 5011pumps, also from E-Bay. These work very well. I have posted some details on how to drive them, and will try the TPH055 on the same inverter. The motor is very similar in principle to that of the TPH055, except it has no winding center-tap, so your simple inverter would not work without an external transformer.

The MDP pumps have a much lower rate , but a much higher ratio and exhaust pressure. I will try using one as a clean scavenger and fore-pump to the TPH055, and hopefully retire my noxious Hg vapor pump, cooling water and cold traps once and for all.
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Alexi Hammond
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Re: Simple turbo pump controller

Post by Alexi Hammond »

Rich,

There is big difference between the RFP2N08L and RFP2N08 transistors. The L sands for "use with logic level driving sources". The RFP2N08L can provide 2-3 amps drain current at 4V gate voltage and the RFP2N08 - only 0.1-0.3 amps.

Any transistor, which can provide at least 2 amps drain current at 4V gate voltage, will work fine in my controller circuit.

Alex
richnormand
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Re: Simple turbo pump controller

Post by richnormand »

Hi Alexi,

first of all many thanks for posting the circuit.

As mentionned in my previous post the only mods that I did (after trying the PLL and such) was to add a full speed and a standby mode switch. I am now waiting for a cheap 4 digit frequency counter (eBay $12) to monitor the pump speed. I was using my good HP frequency meter not only the adjust the pots but to monitor the pump so I figured it would be a good addition.

Here is the spec sheet of the NTE MOSFETs I have been using for over a month. Rock solid, no issues. Looks like they meet the L specs OK. There were cheap and in stock at Allied Electronics.

Looking at your photos: does your pump need the fan? Mine stays cool in the test setup so I removed it.

Best wishes for the New Year.

Edit1: You are right of course about the difference between the two types. Interesting thing is the search software for NTE does not list the L variant in my software version.
Edit2: here is a pix of the setup. The empty space on the board is for the freq module.
Edit3: I did add a note to my original post pointing to your post about the L variant difference. Thanks for catching that.
Attachments
P1094820 (Medium).JPG
nte2382.pdf
(26.03 KiB) Downloaded 583 times
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Alexi Hammond
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Re: Simple turbo pump controller

Post by Alexi Hammond »

Hi Rich,

Yes, the pump gets barely warm after many hours of pumping. However, I left the fan on the pump anyway. The fan seems to be made for 208 or 240V AC. It runs on 120V AC very slowly, but that is enough to keep the pump cold.

Alex
richnormand
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Re: Simple turbo pump controller

Post by richnormand »

I received the eBay frequency meter and here it is.

Just wire the +5V, grounds and signal from pin 3 of the 555 timer in Alexi's controller. You can follow the pump ramp up and slowing down from reading its frequency (1500 Hz is 90,000 rpm). Not bad for $12 and free shipping.
Attachments
P1124821 (Medium).JPG
Richard Hester
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Re: Simple turbo pump controller

Post by Richard Hester »

I may try a simple controller as well, as I have an Alcatel 5010 drag pump coming in the mail, as well as one of uncertain pedigree already in house. If anyone has a copy of the manual, for this one, I'd appreciate it. Otherwise, I'll try contacting Adixen/Alcatel.
AFW
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Re: Simple turbo pump controller

Post by AFW »

Alexei
Thanks for the controller circuit. I notice that on the TPH 055 diagram there is a contact "D" that doesn't have a corresponding connector on the controller. Is this contact left floating? Also, contact "E" is labelled as 15V, but is connected to the +5V line of the controller. Is this a misprint in the TPH055 diagram?
UK purchasers of these pumps should remember that they will have to pay VAT, which, with postage, brings them to about £100. Still a bargain , though.

Tony Webb
richnormand
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Re: Simple turbo pump controller

Post by richnormand »

I think the D to F is a variable resistance as the temperature sensor. I did not connect anything to the D terminal. I'll monitor its value next time I ramp the pump and see what happens. It's most likely used with the OEM controller to ramp down or shut down the pump in case it is overheating .

Hall effect sensor for rotation (E) works fine with 5V in my setup, as stated in Alexi's diagram.

Alexi will probably know for sure.
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Alexi Hammond
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Re: Simple turbo pump controller

Post by Alexi Hammond »

Correct, the pin D is connected to the temperature sensor. When the pump overheats above 50C, resistance between pins D and F drops and the OEM controller shuts down the pump.

The UGN3077 Hall sensor IC has a built-in voltage regulator and works fine with 4.5V to 24V supply voltage.

Alex
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UGN3077.pdf
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ggombert
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Re: Simple turbo pump controller

Post by ggombert »

Has anyone located a source for the connector on these pumps?

Glenn
gpecke
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Re: Simple turbo pump controller

Post by gpecke »

The connectors for these and the Adixen pumps can be found in the Canon catalog. They have to be
ordered as shell and parts.

Seemed to be a nuisance to order a small quantity of these.

I used crimp connect gold plated single pin connectors crimped onto a ribbon cable and insulated
with heat shrink. This is very quick,cheap and easy to do, and the ribbon cable is neat and easy to handle.

The part I used is at http://www.electusdistribution.com.au , part no. hp1260.
Chris Trent
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Re: Simple turbo pump controller

Post by Chris Trent »

I have modified this circuit with a L298 H-Bridge in place of the mosfets. In my case the purpose was to drive the a single phase Molecular Drag pump with no center tap, but the addition should work well for most of the rest of you.

The local electronics surplus shop had a whole box of them, so for me it was an easy call.

In addition to being able to run without a center tap, it adds a couple of nice features; you can add an additional switch for fast motor shutdown, and sense resistors for current control.

I'm planning on posting the modified schematic soon.
DSchultz
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Re: Simple turbo pump controller

Post by DSchultz »

I purchased 20 pieces of the RFP2N08L from Quest Electronics, if anybody wants a pair of them please get in touch with me.
ggombert
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Re: Simple turbo pump controller

Post by ggombert »

Below is the link from DigiKey for a IRL520NPBF logic driven MOSFET that should work well also as a replacement part. The current price for qty1-9 is $1.24. The data sheet can also be downloaded from the link below.
Glenn

http://search.digikey.com/scripts/DkSea ... 520NPBF-ND
Chris Trent
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Re: Simple turbo pump controller

Post by Chris Trent »

I've made a few other changes to the setup I'm using.

First, you may recognize that I simplified the design a bit by using a Full H-Bridge L298 IC.
The Full bridge lets me run single phase pumps that aren't center tapped, as well as get more torque out of those that are. Both circuits in the L298 are used in parallel to increase the power handling capability.

Instead of using Nand gates to power on and off the control signals, I am using the built in enable pin on the bridge. Since the bridge is turned on or off directly I was able to dispense with the Nand (NOT) gates near the end of the circuit. I could have done away with the Nand gates entirely, however I chose to keep the first two and connect them to an interlock circuit. With this particular H-Bridge IC, having both inputs set to the same value shorts the motor outputs to each other, creating a braking effect. I have taken advantage of this to create an emergency stop switch.

Other improvements include TVS diodes near the motor to protect the circuitry.
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TurboController.jpg
ggombert
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Re: Simple turbo pump controller

Post by ggombert »

Hi,

I finally finished a pumping station based on Alexi’s controller and a TPH-055 purchased off of EBay. All of the vacuum fittings are from Lesker’s; the main gauge in the system is an MKS-901P which bottoms out at 10-5 mTorr (also another snag off of EBay). The gauge bottoms out about five minutes after turning on power to the turbo pump.

Most of the parts for the controller were purchased from Digikey and Radio Shack. I also included a cheap frequency counter on the front panel driven off of pin 3 of the 555 timer.

The only thing that I did to the pump was to use some fine grain sandpaper (as Carl suggested in his post) to smooth out some of the dings in the flange of the pump. I actually purchased two pumps of off EBay and both of them are fully operational after following the cleaning instructions (to get rid of the black gunk in the pump) and smooth out the divots in the top vacuum flange.

I will probably replace the grease reservoir in the pump too since it is not too expensive and seems like a modest investment to keep the pump in good working order.

Glenn
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turbostation.jpg
Andrew Seltzman
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Re: Simple turbo pump controller - CONNECTORS

Post by Andrew Seltzman »


The proper connectors for the TPH-055 pump and TCP 035 and TCP 015 controllers are:

Pump body connector: 12-8p or equivalent

Pump side of cable: 12-8s or equivalent (PT06E-12-8S)
http://www.alliedelec.com/search/produc ... U=70143407

Controller side of cable: Harting 09-06-231-6822
http://www.mouser.com/ProductDetail/HAR ... dkYPFT0%3d

Controller board connector: Harting 09-06-131-6922
http://www.mouser.com/ProductDetail/HAR ... RPspXXI%3d

Harting connector data sheet:
http://www.farnell.com/datasheets/26900.pdf

Good luck with the pump controllers, I'll try to build some boards with my CNC mill as time permits.

Andrew
Andrew Seltzman
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Jerry Biehler
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Re: Simple turbo pump controller - CONNECTORS

Post by Jerry Biehler »

If you are looking to make PCBs check out the dorkbotpdx board program. You get 3 quantity boards for $5 per sq inch. Very nice boards too, purple conformal, plated through holes and vias, very fine spacing, silkscreen both sides, and gold plating.

dorkbotpdx.org
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