HarryA

"50Pcs NPN Transistor TO-92 2N2222A 2N2222 Brand New Practical High Quality" (Ebay) Does "Practical High Quality" mean hfe's of almost 100

Hello, I will look at what maybe needed. I am thinking a pair of 555 timers (better but more expensive are the mc1455p timer clock chips). One for the 5 second delay which triggers the second one for the 1 minute on delay. The second one feeds a divide by 5 counter chip for the 5 minutes. For the photo cell perhaps a photo transistor. I just finished a circuit that uses a infrared television sensor to trigger a 555 chip via the television remote. You may want a breadboard and a few jumper leads. Also if you do not have any electronics instruments look for a simple logic probe circuit on the internet; it will use a led as an indicator that the timers are pulsing. It can be fabricated on one end of the breadboard. Then the devil is in the details. Perhaps we can con audioguru into helping with them; he is quite knowable. On second thought one could build LEDs into the circuit so no logic probe would be necessary.

You may wish to look at: Using the TIP120 & TIP125 Darlington Transistors with Arduino https://www.youtube.com/watch?v=wxCJ9NUErwA

Well already having ruined jknittandkarr's thread - sorry jknittandkarr. But another place to spent more money beyond amazon.com and ebay is at the goodwill: see "computers and electronics" off: https://www.shopgoodwill.com/listings/ Don't bid on the solar panel! I am watching

Good question. I test them with my 4 of 5 stars Chinese tester I never buy anything very expensive that I could not toss out. https://www.amazon.com/gp/product/B01M0UXHYY/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1

Yes some people have problems with parts from China but I buy a lot for China. And I never have any problems. I have two items in the "China queue" now. I call it bypassing Wal-Mart and NTE

Go directly to the source: http://www.ebay.com/itm/10pcs-0-8-inch-1-digit-led-display-17-seg-Alphanumeric-Common-anode-BLUE-/311641497467?hash=item488f47df7b:g:nBAAAOSwsB9V87Ec That is where they are all made anyway.

(1)"I have an idea, but I do not know how." What is your idea? (2)"I noticed that the charger for my phone if the phone is not turned on to charge - it does not consume anything. But when I turn on the micro usb connector - then begins to consume." Find; a statement of fact. (3)"Now fit a box that will convert unbalanced audio signal into balanced. But the transformer can not fit in the box of the device and the target mount it in an external box. I do not want a permanent transformer is plugged in. " What is the relationship between sentence (2) and sentence (3)? What are trying to do in sentence (3)?

I tried to buy "30v 10A 110V precision variable dc power supply ..." for 6.97$ and free shipping but it would not let me "buy it now". To good to be true? Worth that as a coffee warmer! http://www.ebay.com/itm/30V-10A-110V-Precision-Variable-DC-Power-Supply-Clip-Cable-Digital-Adjustable-S/222418872649?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D2%26asc%3D41394%26meid%3D98314beb8bcf41c2956f228cf09493ad%26pid%3D100005%26rk%3D5%26rkt%3D6%26sd%3D391694935441

I understand. My electronic books are old enough to vote. Also I find it cost so much for the components that it is far cheaper to buy than build. For example see: http://www.ebay.com/itm/30V-5A-DC-Power-Supply-Adjustable-Dual-Digital-Variable-Precision-Lab-Grade-110V-/391378270581?hash=item5b1ff67975:g:zwcAAOSwUKxYiV76

If you look at [Projects] at the top of the page you may find something helpful: Projects->Power. (Odd there is no link back to the forum page from those pages?)

I am thinking these are color coded capacitors. Photography of part of an early computer.

There are Cannon FH7- xxxx stepper motors that are 24 volts and 1 ampere it that is any help.

If you list the values of the resistors and the type of transistor then one could help you.

You ask for a lot! Start with Ebay.com for transmitters and receivers: see: http://www.ebay.com/itm/Mini-88-108MHz-FM-Transmitter-Module-Wireless-Microphone-Dictagraph-Interceptor/141659602950?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D2%26asc%3D40832%26meid%3D5caec1e4bbe74e2fa065b6379434198a%26pid%3D100005%26rk%3D2%26rkt%3D6%26sd%3D111649741072

http://www.talkingelectronics.com/projects/SolarLight/SolarCharger-2.html

I got a package of 3 boards and jumper wires via Amazon.com and they are crap! Very difficult to insert the jumpers into. I also left my review of them and it was not nice. Also I saw a video on youtube.com where the instructor instructed the students to use needle noise pliers to insert the jumpers into the same type of breadboard. beware of: https://www.amazon.com/UCEC-830-Point-Solderless-Circuit-Breadboard/dp/B01EL7BNEO/ref=sr_1_36/157-6188074-9414127?s=pc&ie=UTF8&qid=1484020623&sr=1-36&keywords=bread+boards

You are not their only customer, they put you on the end of the queue. It takes me about 3 weeks to get electronic gear from China and it is already make!

You points are well made; thanks. On day one I found two voltage boosters on Ebay that gave more than 100 volts so I ordered both of them from China. The first one I received was a 12v dc to 200 v dc. After connecting it up and adjusting it for 200 v I put a 100k resistor across the output and got 2 volts output! It took a one mega-ohm load to keep 200 v. The second one (12v dc to 220 v ac) works well. I connected it to the 220v to 120v step down transformer and into a full wave bridge rectifier with a 100mfd capacitor and got 140 v dc; 9.6 volts input. With a 8.4 v NiMH rechargeable battery I get 128 v dc. So I am happy with that and very surprised that the 50/60 hertz transformer works at all!

Hello from cold and snowy NE PA, In my quest to convert 9 - 12 volts dc into 140 volts dc I purchased a "40W DC-AC 12V To 220V Step-up Transformer Boost Module Inverter" via Ebay. I also purchased a 220 volt to 120 volt 50-60 hertz step down transformer; the type travelers use. But the inverter's output is 38.4k hertz! So my transformer is useless here. I am wondering if one can find a transformer that will handle that frequency and is two to one? I am driving a class D pulse amplifier that outputs 100 Volts peak at a current of 0.10 amperes max. The pulse is 0.4 ms duration at and interval of 2 ms. So I am thinking that I need: 100v * 0.10 * 0.4/2 = 2.0 watts for the amplifier output so I am thinking about 10 watts for the amplifier and the conversion from 120 ac to 140 dc. "

It maybe cheaper to buy one? http://www.ebay.com/itm/1200W-100V-DC-Switching-power-supply-for-LED-Strip-light-AC-to-DC-power-supply-/182370960410?hash=item2a7628041a:g:sukAAOSw6aVUn95M

Is there some way to get read of the %^^*)(*^ pop up with " would you like to receive notifications.... ? I DO NOT WANT ANY!

You could charge the cap. with solar cells during the day and light an LED at night? No batteries required! see: http://www.ebay.com/itm/Maxwell-D-Cell-Power-350F-350-F-Farad-2-7V-Super-Capacitor-Cap-Ultra-Battery/281173041415?_trksid=p2047675.c100009.m1982&_trkparms=aid%3D888007%26algo%3DDISC.MBE%26ao%3D1%26asc%3D38530%26meid%3D4d48fa267f404223bb70c8c93e334efc%26pid%3D100009%26rk%3D1%26rkt%3D1%26sd%3D161240113620 man that is some url!

Most likely you have a few screws loose John see: http://en.allexperts.com/q/Electrical-Wiring-Home-1734/2009/6/Circuit-reads-60-volts.htm also search on: "electrical problem 60 volts on 120" good luck. addendum: As this a common problem could a poor connection between copper (or better yet corroded copper; copper oxide) and plated steel act as a diode and the the results (at very low current) is a half wave rectifier? That would yield the 60 volts rms. ref: http://www.tutorvista.com/physics/half-wave-rectifier-calculation