Linear Headlight motor Success! (Page 4/5)
JMTUT SEP 25, 11:06 PM
Unfortunately, I only have the cheap Harbor freight meter so I can't measure current draw.
theogre SEP 26, 04:38 AM

quote
Originally posted by JMTUT:
Unfortunately, I only have the cheap Harbor freight meter so I can't measure current draw.

Don't bother... If your new motor setup is fast... Likely will have same problem trying to read Amps on Gen1 or Gen2 setups. I have several meters of different types are all have problems reading fast events.

A. You have 3 numbers that matter...
1. Starting current, AKA Inrush Current, when a motor etc starts up.
2. Running current. When you see Amps Spec on a motor etc, this is where number comes from.
3. Stall current when motors Jams or at End of Travel.
1 & 3 can be 2 to many times the Running Current.
Example: Engine Starter rated at 1.5kw eats ~ 120a at 12.6v running... But inrush current when you first turn the key is easily 2x to 4x of that number.

B. Most meter displays are not quick enough to read. Gen2 motors run ~ ⅔ of One Sec. Gen1 working right are slower but not enough for most meters.
Most Analog meters have meter protection so needle can't slam and can't read fast events. A-meters w/o this can't read them either because needle overshoots the real value for fast events.
Most Digital Meters of any kind only update their screens 1 or 2 times per sec.
Max hold function either reads starting or stall current and you have no clue which value it reads as max.
IOW most meters can't tell amp draw to tell you much here or program an "arduino board."
Would need a scope meter or storage O-scope w/ current shunt to capture load curve for opening and closing a door.

C. If you try to emulate Gen2 board... You likely deal w/ all three current values.
Board need to pass 1 and 2 and kill power for 3.
Problem is 1 can be = or higher then 3 so is likely not a simple as just turning on power to the motor and monitor amp load.
Simple timer doesn't help when a motor is stalled for any reason. The Whole motor may not get hot in 1 to 5 sec but Brushes and other parts can and even burn out in short order.
Gen2 "Backup" timer is to kill power if motors have no load because of broken lift parts etc or module is "bad" and can't read motor amps to prevent motor melting @ EoT or jamming.
Chris Eddy SEP 26, 11:02 AM
There is one more piece of the puzzle to consider.. when the motor turns off, there is usually a back EMF pulse. Since the switch opened, the current is converted into a high voltage, arcing across the contacts and making short work of them. The key is to use diodes in the right orientations so that when the motor turns off, the current flows through the diodes. Just google back emf protection.
theogre SEP 26, 11:59 AM

quote
Originally posted by Chris Eddy:
There is one more piece of the puzzle to consider.. when the motor turns off, there is usually a back EMF pulse. Since the switch opened, the current is converted into a high voltage, arcing across the contacts and making short work of them. The key is to use diodes in the right orientations so that when the motor turns off, the current flows through the diodes. Just google back emf protection.

Simple Diodes won't work for motor that spin both ways. Same issue for PW motors that have nothing to stop motor back EMF that eats up many PW Switches. (Not only a Fiero problem.)

Gen2 Module have 330Ω 1/8w or 1/4w resistors to do this and does work for decades. (R14 and R15 in http://www.fiero.nl/forum/F.../HTML/140432.html#p9 ) Can run very small watt resistors because motor on "shorts them out" then turn off the motors the resistor see Milliseconds to Microseconds of Back EMF that can't heat them to burn out.
Can run MOV and others to maybe to do it better and doesn't care about polarity.

ETA--> I'm skipping many points to emulate Gen2 w/ Arduino of any kind like most will eat a lot more power vs. real Gen2 board w/o making them sleep when not needed. W/o proper sleep design (is often is a function of hardware and software design.) Arduino and support chips can drain the battery fast enough to not start the car after only a week or three. Like a switch to dome/trunk light is stuck on.

[This message has been edited by theogre (edited 09-26-2019).]

JMTUT SEP 26, 03:19 PM
The linear motors have diodes installed in line with the limit switches.
theogre SEP 26, 07:09 PM

quote
Originally posted by JMTUT:
The linear motors have diodes installed in line with the limit switches.

Depending just how they are wired... These Diodes likely do little for back EMF wiring in series w/ any switches.

Diodes for back EMF are wiring in parallel w/ a coil w/ Plus side of diode to Plus power.

(Gen2 R14 and R15 resistors are wired same but in the module not in the motor itself.)

One direction Motors work same but when motor/coil is reverse powered the diode most likely will die but coil still works. In fact many replace TC Clutch solenoid wrong way around, blow the diode in it then have problems w/ switches and even the ECM w/o back EMF protection. Many have dead AC clutch diode have same problems and why Dorman Wells(@RA) etc have AC diodes as PnP or pigtails parts. (One Wells' pic barely shows the diode under the heat shrink.)

Other devices may look like simple diodes but are wired same for surge and back EMF protection.
Some of these devices may like reveres DC and AC power.
I don't think Bipolar/Bi-directional TVS "Diodes" were available in 80's. Even if was available, the GM bean counters could fight them costing even a fraction of a cent more then the resistors used on Gen2 board.
Chris Eddy SEP 26, 11:01 PM
{QUOTE}Simple Diodes won't work for motor that spin both ways. Same issue for PW motors that have nothing to stop motor back EMF that eats up many PW Switches. (Not only a Fiero problem.)

Gen2 Module have 330Ω 1/8w or 1/4w resistors to do this and does work for decades. (R14 and R15 in http://www.fiero.nl/forum/F.../HTML/140432.html#p9 ) Can run very small watt resistors because motor on "shorts them out" then turn off the motors the resistor see Milliseconds to Microseconds of Back EMF that can't heat them to burn out.
Can run MOV and others to maybe to do it better and doesn't care about polarity.

ETA--> I'm skipping many points to emulate Gen2 w/ Arduino of any kind like most will eat a lot more power vs. real Gen2 board w/o making them sleep when not needed. W/o proper sleep design (is often is a function of hardware and software design.) Arduino and support chips can drain the battery fast enough to not start the car after only a week or three. Like a switch to dome/trunk light is stuck on.

[/QUOTE]

Using 4 diodes, you can arrange a back EMF protection. Google full bridge with back EMF.
The 330 ohm resistor is not really for soaking up back EMF.. a resistor and cap in series can be a "snubber" to do that though. They probably found that it kept the voltage spike down to an acceptable level though, and saved $$ leaving the caps out.
And you could put Transient Suppression Diodes (back to back) across the motor to do that too.
Dennis LaGrua APR 11, 05:46 PM
This thread needs to be revisited but specifically for a replacement for the GEN 1 motors. If your Gen1 motor breaks replacements are unavailable and if the motor is not rebuildable then there are no alternatives. I'd like to start using a Linear actuator on my 85GT. The mounting seems straight forward but the electrical circuit will need some work.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

Dennis LaGrua APR 12, 12:28 PM

quote
Originally posted by Dennis LaGrua:

This thread needs to be revisited but specifically for a replacement for the GEN 1 motors. If your Gen1 motor breaks replacements are unavailable and if the motor is not rebuildable then there are no alternatives. I'd like to start using a Linear actuator on my 85GT. The mounting seems straight forward but the electrical circuit will need some work.




Actually the Gen 1 circuit already reverses the polarity. All we need to do here is to fuse the supply leads and do the mechanical mount. Should be easy.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

TheDuke APR 12, 12:58 PM
how can i tell if i have gen1 or gen 2 HL? i have an 86 SE 2.5