Author Topic: ESD 5500E engine speed controller unit  (Read 977 times)

BruceM

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Re: ESD 5500E engine speed controller unit
« Reply #15 on: July 17, 2019, 02:46:38 AM »
A two piece steel sheet "rim" bolted to the hub with holes or slots would also suffice to keep a inductive coil pickup system happy.  I did experiment with one before going another way.

I instead used a Cherry brand gear tooth sensor on my CS for speed sensing; it uses a tiny magnet within the unit and hall sensor to detect teeth or slots in ferrous materials. The spokes on the flywheel sufficed, I didn't have to use magnets.  I use the PICaxe 40X2 chip to compute RPM in this manner for starting and engine monitoring.  The generator isn't always operated as it's a dual air/genny setup. 

For my neighbor's setup we used 4 tiny magnets on the CS flywheel hub just as Glort suggested, with a hall effect sensor (about a buck each) and a little frequency to voltage IC to turn it into a DC voltage that could be easily remotely monitored via analog panel meter.


dieselspanner

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Re: ESD 5500E engine speed controller unit
« Reply #16 on: July 17, 2019, 07:24:54 AM »
I don't know what my mate did for the rev counter, but the pick up is from a hall effect switch with four magnets mounted on the camshaft retaining collar. The whole thing then is hidden safely under the cover.
a very tidy set up

Cheers
Stef
Tighten 'til it strips, weld nut to chassis, peen stud, adjust with angle grinder.

AdeV

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Re: ESD 5500E engine speed controller unit
« Reply #17 on: July 17, 2019, 07:51:11 AM »
In my non existent knowledge of engine control, counting teeth is usually done for timing purposes, so the computer knows where the engine is in it's rotation for fuel injection, spark, variable cam timing etc.

Even then, it doesn't count teeth. On most flywheels that are used by ECUs to set timing, there's a set of "fins" that kinda look like teeth, but are actually a make/break for a sensor. The gap between make/break tells the computer how fast the engine is turning at any given instant, and there's a single gap where one "fin" is missing; this gives the ECU the absolute rotational position of the engine. That's still not quite enough for a four-stroke though... so there's also one (or sometimes more) cam sensors; these tell the ECU which part of the rotation cycle it's on. So before your engine fires up, first it reads the crank sensor, then it reads the cam sensor, and once it's got known good signals to both, it can start applying fuel/ignition as needed.

If you google for "BMW S62 flywheel", look at some of the lightweight wheels, they clearly show the "tabs" that I'm on about, just inside the ring gear. I tried linking to a picture, but t'interwebs is being a PITA just now.
Cheers!
Ade.
--------------
1x Lister CS Start-o-Matic (complete, runs)
0x Lister JP4 :( - Sold to go in a canal boat.

mikenash

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Re: ESD 5500E engine speed controller unit
« Reply #18 on: July 17, 2019, 08:55:41 AM »
Dunno if it's worth mentioning, but some of the big diesel engine controllers we use take a RPM signal off the alternator.

More revs = more hz I guess

BruceM

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Re: ESD 5500E engine speed controller unit
« Reply #19 on: July 17, 2019, 04:10:58 PM »
The inductive type pickups are also quite common - an oscillator circuit is applied to a small coil in the sensor, the presence of ferrous material close to the coil changes the inductance of the coil, which is sensed.  They use more power and generate a fair bit of EMI.

For my neighbor's spark modified CS clone, I decided to save a bit of power by quashing the wasted spark. I didn't think of the nicer far side camshaft -magnet-hall effect method Stef showed, but instead sensed a magnet on the IP cam follower.  That hall switch powered the second one sensing a magnet on the flywheel.  That was the trigger for a 555 cmos timer which generated a pulse for a GM spark module.  Pulse width determined coil charging time, spark at falling edge of pulse, so flywheel magnet location had to lead spark timing by the fixed coil charging time.  Took some experimenting to get the timing just right, facilitated by fast setting cyanoacrylate.
« Last Edit: July 17, 2019, 04:12:42 PM by BruceM »

glort

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Re: ESD 5500E engine speed controller unit
« Reply #20 on: July 17, 2019, 11:30:35 PM »

I needed a comparator chip for a stand alone PWM solar heating circuit I'm building and bought 20x 555's on fleabay for  $1.20 Au Delivered.
I could have got 10 for $1 but for the extra .20C, I thought I'd buy a lifetime supply ( to go with all the other components I have a life time supply of sitting in boxes) and be done with it. 
I was paying more than a dollar each for those things when I was a kid. Can't believe how cheap they are now! They MUST be loosing money at that price just on processing the order.

Of course if I bought them from the US, the postage would have cost me $ 89.95. >:(

Might be able to use a couple to drive a fuel injector and make myself a Pulse Jet engine that is electronicly driven.
Save on those pesky reed valves and make tuning a valveless a lot easier.  :laugh:

BruceM

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Re: ESD 5500E engine speed controller unit
« Reply #21 on: July 18, 2019, 12:12:18 AM »
Most of the old famous ICs and microprocessors are still being made.  Not so with power transistors of various sorts; they pass into oblivion rather quickly. 

The newer micropower components by Microchip are damned impressive.  Quiescent currents of a few microamps for quad comparators, and around 20 uA for a 5V op amp with 100K bandwidth.  Others have them too, some are rail to rail inputs and outputs as well. Analog has never been better.

The range of applications for MOSFETs keeps getting bigger too, several manufacturers now provide full SOA data (safe operating area) for linear operation.  I converted my linear PV charge regulator over to MOSFETs instead of Darlington Bipolars last year...by luck of design, no circuit changes were needed but the power requirements dropped substantially, and the capacity increased nicely as well.

Alas, wildfire smoke has me laid low, health wise, so projects are on hold.