Location of Passive RFID on Motor Vehicles

Started by Bret Cahill in sci.electronics.basics4 years ago 5 replies

Supposedly the active devices are often near the rear view mirror. Where are the passive RFIDs typically located when factory installed?

Supposedly the active devices are often near the rear view mirror. Where are the passive RFIDs typically located when factory installed?


Triac efficiency

Started by Anonymous in sci.electronics.basics2 years ago 10 replies

Hi everyone, When regulating the power to a motor or light, does the triac do so efficiently or does it dump the unwanted power as heat, as a...

Hi everyone, When regulating the power to a motor or light, does the triac do so efficiently or does it dump the unwanted power as heat, as a linear voltage regulator does? Thanks, Michael


How to slow down RPM of miter saw?

Started by John Doe in sci.electronics.basics5 years ago 48 replies

The motor runs on standard USA 120 V 60 Hz, 14 A, at 5500 RPM. What's the easiest way to slow down the RPM? What about simply adding a...

The motor runs on standard USA 120 V 60 Hz, 14 A, at 5500 RPM. What's the easiest way to slow down the RPM? What about simply adding a diode in series on the power cord? Any advice, references, and links would be appreciated. Thanks.


Dummy book on motors

Started by W. eWatson in sci.electronics.basics8 years ago 1 reply

I'm looking for some reasonably introductory book on motors, relays, gears, load, torque, and such. (See my Moving a Dome post on 11/14 as to...

I'm looking for some reasonably introductory book on motors, relays, gears, load, torque, and such. (See my Moving a Dome post on 11/14 as to what I'm attempting to do.) I do have a book by Hughes titled Electric Motors and Drives does a good job at motor fundamentals.


Rudimentary PC USB oscilloscope?

Started by John Doe in sci.electronics.basics4 years ago 20 replies

My main question is about PC USB-based oscilloscopes. The rest of this is specific to my problem(s) and may be overlooked. I'm using cordless...

My main question is about PC USB-based oscilloscopes. The rest of this is specific to my problem(s) and may be overlooked. I'm using cordless drills to power electric bicycles. I have one built. It works but is underpowered. I am building a better one using a DeWalt DCD995. Some nice electronics included in that drill, a stout (very tight turning) brushless motor with a controller. ...


Capacitor-run induction motor windings

Started by Anonymous in sci.electronics.basics2 years ago 5 replies

Hello, I'm hoping to convert old household induction motors to brushless motors basically by replacing the rotor with magnets. However I'm...

Hello, I'm hoping to convert old household induction motors to brushless motors basically by replacing the rotor with magnets. However I'm having difficulty understanding the stator winding patterns. I need to isolate the phases obviously. Any suggestions? Even if they are two phase instead of three phase, that is useful too. Thanks, Michael


Can someone translate this ? Russian to English

Started by gm in sci.electronics.basics2 years ago 11 replies

Hi to all. College of mine bought some Chinese motor controller but i can get any addition infos on Chinese site. Luckily i found that someone...

Hi to all. College of mine bought some Chinese motor controller but i can get any addition infos on Chinese site. Luckily i found that someone in Russia is using the same controller and he has wrote how to connect, but it in Russian language. Can someone please translate this ? https://ibb.co/i6zZ6w Thank you in advance !


MOSFET Question (Buzzer, Motor Drive, LED Driver) - Advice.

Started by Anonymous in sci.electronics.basics4 years ago 5 replies

Hello everyone I hope you are having a good day. I had three questions that correspond to the 3 sections of the schematic shown below. ...

Hello everyone I hope you are having a good day. I had three questions that correspond to the 3 sections of the schematic shown below. Question 1.) There is a piezoelectric buzzer that is shown below that gets connected to a microcontroller through resistors R9 and R10. Here is the part: http://www.digikey.com/product-s... Usually on a beeper I would just apply power


Circuit design needed

Started by Mark in sci.electronics.basics5 years ago 5 replies

I need to build an inexpensive circuit to open and close a 3volt DC power source at about 15 minute intervals. The circuit would need to open,...

I need to build an inexpensive circuit to open and close a 3volt DC power source at about 15 minute intervals. The circuit would need to open, then close again after a short delay say 500 milliseconds to a few seconds. I had thought about doing this mechanically with a slow rpm motor, gears and a micro switch, but there must be a circuit that can do this. Thanks


Servo motor recommendation sought

Started by D.M. Procida in sci.electronics.basics4 months ago 2 replies

For my plotter project I have experimented with a variety of different servo motors. Very cheap analog micro servos work very well (I have...

For my plotter project I have experimented with a variety of different servo motors. Very cheap analog micro servos work very well (I have been using Tower Pro SG90s), as you can see from the images on the site, but digital versions do not, because they are too twitchy. I'd like to try with some different digital (more expensive) servo motors to see if the


efficiencies of appliance 3-phase brushless motors?

Started by Anonymous in sci.electronics.basics1 year ago 26 replies

Hello, What is the ballpark efficiency range of washing machine or clothes dryer three-phase 110-volt AC motors? I'm debating tearing a...

Hello, What is the ballpark efficiency range of washing machine or clothes dryer three-phase 110-volt AC motors? I'm debating tearing a broken washing machine apart for the motor and controllers but was curious if the efficiency is too low to bother. Thanks, Michael


VFD for single phase induction motor?

Started by Anonymous in sci.electronics.basics1 year ago 2 replies

Is this possible? I have a customer, a glass artist, who uses several very nice but old glass grinding machines. There are only 4 speeds...

Is this possible? I have a customer, a glass artist, who uses several very nice but old glass grinding machines. There are only 4 speeds on these machines and he would really like more speeds. He has a newer machine with a VFD on it and asked me how he could get the same thing on his old machines. I told him he really needs to change motors to 3 phase. But he is loathe to do that. I can see w...


Major Differences In Small Engine Coils

Started by Bret Cahill in sci.electronics.basics8 years ago 7 replies

Maybe the voltages vary somewhat for different point and plug gaps but is it enough to make any difference? . Supposedly Honda no longer...

Maybe the voltages vary somewhat for different point and plug gaps but is it enough to make any difference? . Supposedly Honda no longer makes the coils for their 100 outboard, a 2 cylinder 4 stroke engine. Isn't it likely that other small engines, say from riding lawnmowers, use coils that are pretty much the same? For that matter couldn't a motor vehicle coil work? Bret Cahill ...


Whole house fan motor

Started by telengard in sci.electronics.basics7 years ago 37 replies

Just recently purchased a house and it has a whole house fan. Unfortunately, the folks who installed the A/C disconnected the motorized louvers...

Just recently purchased a house and it has a whole house fan. Unfortunately, the folks who installed the A/C disconnected the motorized louvers to get into the crawl space a couple months ago and I'm not sure exactly how it was wired. In the crawl space there is a black (which had a wire nut on it) and bare wire and a white wire which looks like it was curled up to not use it (it is not stri...


Cycling Safety Transponder, 15m - 45m Range

Started by Bret Cahill in sci.electronics.basics2 months ago 14 replies

The Bike Shield app never caught on because of spotty data in scenic areas. Also some cyclists don't like posting their GPS. A transponder is...

The Bike Shield app never caught on because of spotty data in scenic areas. Also some cyclists don't like posting their GPS. A transponder is the same thing as a bike light except it's at radio frequencies, works around curves day or night, and motor vehicles tune in to the frequency posted on the "Share the Road; Get Cyclist Alerts At AM 1090" sign. It would require a dedicated


OT electronics nostalgia, NYC subway system

Started by default in sci.electronics.basics3 years ago 2 replies

http://nycsubway.org/wiki/Power_Generation Wonderful site of the history, design, construction etc. of the NYC subway system. Vintage pix of...

http://nycsubway.org/wiki/Power_Generation Wonderful site of the history, design, construction etc. of the NYC subway system. Vintage pix of the 75 RPM Steam piston plants that supplied 25 Hz 11 KVAC to the substations and rotary converters and motor-generators that supplied 600 VDC to the 'third rail.' During the summers my buddy and I would plunk down seven cents, and get on the 242 n...


Relaxation Oscillator as a perfect example of regenerative feedback

Started by Patrick Chung in sci.electronics.basics5 years ago

Relaxation Oscillator circuit is a perfect example of regenerative feedbac= k that is special case of positive feedback. Simple and efficient,...

Relaxation Oscillator circuit is a perfect example of regenerative feedbac= k that is special case of positive feedback. Simple and efficient, this cir= cuit is practical for students labs and still applicable in the blinking tu= rn signal on motor vehicles, use in stroboscopes and as the time base in ea= rly oscilloscopes and television receivers. Read more: http://www.cirvirlab.com/in...


DC motor pwm, mosfet barbecue, etc.

Started by Anonymous in sci.electronics.basics7 years ago 12 replies

Hi, I built a pwm circuit (200 Hz switching frequency) using 12V as a supply, also using around 12V to the gate of an IRF530 mosfet. I tested...

Hi, I built a pwm circuit (200 Hz switching frequency) using 12V as a supply, also using around 12V to the gate of an IRF530 mosfet. I tested it with an automotive turn signal light (about 1 amp) and it worked just fine (without a heat sink on the mosfet). I then tried using it to control a 12V tire inflator/compressor (about 4 amps). The inflator operated fine, but then when I felt the mo...


Soldering 550m of copper wire

Started by Goran in sci.electronics.basics7 years ago 46 replies

I have to solder 550 - 600m of 1mm copper wire. Wire must be completely covered with solder. It will take some time to do this on regular...

I have to solder 550 - 600m of 1mm copper wire. Wire must be completely covered with solder. It will take some time to do this on regular basis ( with soldering iron ) so i was thinking to make some kind of slot in some aluminium housing and melt the lead alloy in it. Then i can put the wire in it and draw it slowly throe this slot. Additionally i can set some stepper motor on the othe...


Cycling Transponders and/or Safety Apps

Started by Bret Cahill in sci.electronics.basics4 years ago 4 replies

Bike Shield gives out the GPS of a cyclist or motor cyclist to safety minded motorists. A beep or something warns motorists when a cyclist is 20...

Bike Shield gives out the GPS of a cyclist or motor cyclist to safety minded motorists. A beep or something warns motorists when a cyclist is 20 meters around a blind curve on a "scenic" or "historical" highways. (Historic = no bike lane, no shoulder, no grading, no guard rails just a sheer cliff with blind curves on narrow lanes.) Alternatively, if privacy is an issue, motorists could be...