Latest threads in Hobby Electronics Basicsshow only best voted threads
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Testing a ZNR and other
Thanks to everyone for all of the help that I have received through this group. This one and the Pinball newsgroup are the most helpful newsgroups there are. I have a few components that I am having...
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15 years ago
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DIY laser schematic
A friend of mine dug up this schematic he wants to build with his son. If you scroll down a bit, you'll see an annotated schematic. It shows the +9V battery and on the right side it has Positive side...
8
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15 years ago
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mini usb 5v datasheet
Dear all, Can any one tell me the data sheet of 5V mini usb 5 pinout (THA component) ?
1
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15 years ago
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JFET on resistance?
Hi; Is there a way to figure out the R(on) of a JFET when this parameter isn't specified in the data sheet? Thanks
21
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15 years ago
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21 | |
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Driving a transistor base from a voltage divider
Hi, I am trying to determine the operating specs for operating a transistor base (as a switch) from a voltage divider. What I am trying to figure out is the appropriate values of R1 and R2, given a...
22
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15 years ago
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22 | |
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voltage comparator question
Hi All I am controlling the output of a bicolor LED using a dual comparator (393), however when the input voltage hovers around the ref voltage, the LED starts to flicker between colors, and...
6
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15 years ago
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How to test speaker ohms?
I want to replace the midrange of a Fisher speaker model ST-440 "Studio Standard Series". No idea what vintage it is - maybe 80's or 90's. What's on the back is SB-80521-1 L81TNK AFAIK it's a factory...
36
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15 years ago
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Can fixed-voltage regulators be paralled up?
Can fixed-voltage regulators be paralled up to cope with higher currents. (eg the 2 Amp L78S24CV 24 Volt fixed voltage regulator)? Could I use 5 of these in parallel to supply 10 amps?
4
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15 years ago
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power on/off pop problem
I'm using a dbx active crossover feeding a couple old adcom amps. I've rigged it all to go on and off controlled by my "pre-amp" power. But I get a substantual power on and off pop from both amps. It...
9
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15 years ago
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Can DC voltage be doubled to drive 10 V relay ?
Have some cheap 10 volt relays. My project will consist of 74HCT gates supplied by 5 volts. Is there any way of doubling 5 volts DC ? Otherwise I'll need a power supply that supplies multiple...
15
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15 years ago
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15 | |
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Need advice on designing an eight Layer PCB
I=92m designing an eight Layer PCB Board that has LVDS signals in frequency of 700Mbps. I have read lots of Document regarding Impedance Controlled PCB routing. The desired impedance is 100 Ohm as I...
1
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15 years ago
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Chinglesh? 0V to 25V 10A power supply
When friends want Variable power supply Switching Regulator Circuit. I thinks this circuit may like friends certainly. It can Adjustable from 0V to 25V at current 10A. By have the prominent point...
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15 years ago
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Power Supply vs Adaptor
My DSL modem came with an adaptor. It burnt. I bought a new cheap adaptor, it burnt too and the next one too. So some one told be to buy a 9V DC power supply. He said unlike adaptors they dont get...
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15 years ago
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how can I deal with a current spike?
Hello, I'm going to be driving a capcitive load out from a couple opamps, both the opamps are acting as buffers, and normally my capacitve load will have a very small current through it... but...
12
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15 years ago
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Repairing CDI ignition unit
Anybody know how a CDI ignition system for a small petrol engine works? I have taken one of them apart, but managed to destroy and lose some information in the process (hammer and chisel). The circuit...
19
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15 years ago
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