It Wouldn't Take Much Affer Marketry Circuitry To Mitigate This Problem

Started by Bret Cahill in sci.electronics.basics3 months ago 1 reply

No need to spend $5K on a Powerwall. Home owners wif grid ties should be able to flip a switch when the utility goes AWOL. Then they can...

No need to spend $5K on a Powerwall. Home owners wif grid ties should be able to flip a switch when the utility goes AWOL. Then they can refreeze the cheese & meat in the refrigerator and charge up some smart devices when the sun is shining. Gavin, are you listening? Any prof at any EE dept will tell you this is low hanging fruit. https://news.bloombergenvironment.com/environment-and-en...


Isolation transformer?

Started by Bob Engelhardt in sci.electronics.basics3 months ago 19 replies

I was looking for a 120-120 isolation transformer on eBay and I kept finding 120-240/480 transformers. There are 2 secondaries on these...

I was looking for a 120-120 isolation transformer on eBay and I kept finding 120-240/480 transformers. There are 2 secondaries on these (connect in parallel or series). It occurred to me that I could use one of these as a 120-120 by using one secondary as input and the other secondary as output. I know that this is theoretically possible, but are there practical reasons why it wouldn'...


Colpitts oscillator

Started by riccardo manfrin in sci.electronics.basics4 months ago 5 replies

Hi, I'm following instructions here (https://www.wikiwand.com/en/Colpitts_oscillator#/Practical_example) to build a discrete components above...

Hi, I'm following instructions here (https://www.wikiwand.com/en/Colpitts_oscillator#/Practical_example) to build a discrete components above MHz oscillator. I could not find a 150nH inductance so I used one I found on spare components, which has I think rather larger inductance. The circuit appear to be working well and outputs around 10MHz, but in order to see the frequency


Wanted: A 'joule thief' style circuit design...

Started by ~misfit~ in sci.electronics.basics4 months ago 15 replies

... that I can use to drain alkaline cells and push the 'charge' into either a lithium-Ion cell (for a flashlight), a phone or a powerbank. I...

... that I can use to drain alkaline cells and push the 'charge' into either a lithium-Ion cell (for a flashlight), a phone or a powerbank. I have a combined wireless doorbell - inside/outside thermometer that I quite like. Unfortunately it won't run on NiMH cells and only uses alkalines down to 1.33v. (It's the only thing I have that doesn't run on rechargeable cells.) The sender uses...


wireless sensors

Started by Ralph Mowery in sci.electronics.basics4 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.basics4 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.basics4 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.basics4 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.basics4 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.basics5 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 ...


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