wireless sensors

Started by Ralph Mowery in sci.electronics.basics6 months ago 5 replies

I bought a wireless inside/outside temperature/humidity display. I got to thinking about the outside sensor. I am almost sure the sensor...

I bought a wireless inside/outside temperature/humidity display. I got to thinking about the outside sensor. I am almost sure the sensor does not transmit all the time because of only 2 AAA batteries. Any thoughts on how often the sensor updates and sends data back to the inside unit ? Once a minuit, once ever 10 , or maybe it is when the temperature changes a half to one degree ...


LED RF Noise Evaluation

Started by ABLE1 in sci.electronics.basics7 months ago 8 replies

Hello, I have experienced what seems to be RF Noise that is generated from LED lighting. I don't have the exact spec's but just...

Hello, I have experienced what seems to be RF Noise that is generated from LED lighting. I don't have the exact spec's but just wondering if anyone here knows of what to look for as to packaging labels or spec's on LED lighting, if any. The issue just came up today when talking to a customer that has just recently had LED lights in there bar. He says now there is noise that is being ...


All Ob A Sudden, Starter Motors Is So Small & Light You Can Carry 'em Home In A Filmy Shoppin Bag

Started by Bret Cahill in sci.electronics.basics7 months ago 4 replies

Summin didn't look right. The replacement starter motor was 2/3rds the dia of the original, mebbe haf the wait. I tink, WTF? Weren't all them...

Summin didn't look right. The replacement starter motor was 2/3rds the dia of the original, mebbe haf the wait. I tink, WTF? Weren't all them optimum nummers well settled back in the early Nicolacene? I toght, heck, no need to strap it onto the bike rack. I'll just stick hit into a shoppin bag. Affer an easy installation, the thang _akutually werked._! Affer about 2 days a theory he...


12 Vdc led running hot

Started by AK in sci.electronics.basics7 months ago 11 replies

I bought some 12 VDC 5 mm red leds. They work find but... when I touch the wires going into the led, they were hot enough that I had to...

I bought some 12 VDC 5 mm red leds. They work find but... when I touch the wires going into the led, they were hot enough that I had to remove my hand. That does not seem normal. Thanks.


Independence of Capacitance from Dielectric

Started by Hamid V. Ansari in sci.electronics.basics7 months ago 2 replies

Hi, A simple carelessness has caused the famous formula for the electrostatic potential to be written wrongly while in its correct form we must...

Hi, A simple carelessness has caused the famous formula for the electrostatic potential to be written wrongly while in its correct form we must use a term showing electrostatic field arising only from the external charges not also from the polarization charges. So, capacitance of a capacitor does not at all depend on the dielectric used in it and depends only on the configuration o


Anyone with plc experience?

Started by default in sci.electronics.basics7 months ago 5 replies

I was looking for a ready made timer for a hydroponic system I'm tinkering with and came across some el-cheapo PLCs on Amazon, and figured this...

I was looking for a ready made timer for a hydroponic system I'm tinkering with and came across some el-cheapo PLCs on Amazon, and figured this would work lots better than a timer that would need a lot of additional circuitry to adapt. The catch is that they mention a programming software that is from Mitsubishi and costs $500+ . After looking around I found some cheaper alternatives but ...


Frequency counter

Started by Peter Percival in sci.electronics.basics7 months ago 29 replies

I'd like to buy a frequency counter but I was afraid they'd cost thousands. Apparently, "only" hundreds -...

I'd like to buy a frequency counter but I was afraid they'd cost thousands. Apparently, "only" hundreds - https://uk.rs-online.com/web/p/products/6654919/?tpr=2. Any recommendations? -- "He who will not reason is a bigot; he who cannot is a fool; he who dares not is a slave." - Sir William Drummond


Will this work safely?

Started by Terry Pinnell in sci.electronics.basics7 months ago 10 replies

Pressing the door button of my commercial wireless door bell causes the mains-powered speaker unit in the hall to chime. Rather than buying...

Pressing the door button of my commercial wireless door bell causes the mains-powered speaker unit in the hall to chime. Rather than buying another speaker unit I thought I'd make a simple extension myself. I'd then get an identical chime in my workshop. With difficulty I was able to get access inside the unit and connected a couple of wires in parallel with its tiny speaker, like this: ...


GFCI/lightening

Started by default in sci.electronics.basics8 months ago 2 replies

I had a lightning strike hit an antenna mast and it took out a lot of electronics in my house. It actually popped circuit breakers in the house...

I had a lightning strike hit an antenna mast and it took out a lot of electronics in my house. It actually popped circuit breakers in the house along with taking out the TV, modem, KVR switch, low voltage LED lighting, and several power supplies. The interesting thing was the circuit for the Ground Fault outlet that feeds my outdoor workbench was kaput, but didn't show any signs of being ...


Inductance calculations

Started by Peter Percival in sci.electronics.basics8 months ago 5 replies

Somewhere there must be a formula for the inductance of a hand-wound coil. Air core, one layer of wire (of given swg) close-wound, diameter of...

Somewhere there must be a formula for the inductance of a hand-wound coil. Air core, one layer of wire (of given swg) close-wound, diameter of former (cardboard, probably inside of toilet paper roll), length of coil,... (what else?), therefore inductance equals ...


Ask a Question to the Electronics-Related community

To significantly increase your chances of receiving answers, please make sure to:

  1. Use a meaningful title
  2. Express your question clearly and well
  3. Do not use this forum to promote your product, service or business
  4. Write in clear, grammatical, correctly-spelled language
  5. Do not post content that violates a copyright