Recent Posts

1

General Technical Chat / Re: Model Trains

« Last post by floobydust on Today at 03:03:07 am »

I wonder how much current the loco's use? Including the headlight and smoke generator.

O-scale train set I had, it was powered by a Louis Marx 1209 toy transformer. LV AC variac, no circuit breaker or fuse that I remember. It seems to have been a Marx train set, I'm not sure.
Made quite a few sparks on the tracks. Tried cleaning them with steel wool, uncle's idea. That lit up and started burning. Scared the shit out of me.
Then the figure-8 crossover shorted out intermittently and the track got red hot and smoked. The train set from hell lol. A manly model train, that's for sure.

Years later went N then HO and that was plastic baby in comparison.

2

Test Equipment / Re: SDS800X HD Wanted Features

« Last post by electronics hobbyist on Today at 02:58:51 am »

Yes, I will list a top x later, thank you for your suggestion.
When a suggestion is satisfied, the top x will be updated again.

3

Beginners / LM317 Based Digitally Controlled Power Supply

« Last post by EthannCraftt on Today at 02:57:43 am »

Hello. I'm looking to construct a digitally controlled power supply. I have a circuit drawn up with a PWM voltage control circuit of my own design, and the current control design that Dave drew on his PSU series hooked up to the input of the second LM317.

After being plugged into a circuit simulator, it seems to have really weird behavior even though both circuits work great on their own. Any help??? Schematic below.

(The +5v inputs are where the PWM will be inputted. An RC filter will be added in the final design. The 1ohm resistor to the far right will also be removed.)

4

Repair / Re: SOLVED : Help with troubleshooting a Hypex SMPS400A400

« Last post by beatman on Today at 02:46:18 am »

RD samwha 105c standart series.The worst  thing for smps input or output and pwm amps.I use tons of these for recap cheap mixers and cheap crap amps that don't worth anything better.

5

Beginners / Re: buying a oscilloscoop

« Last post by BillyO on Today at 02:39:27 am »

If you can arrange a bit more I'd strongly suggest something like the Siglent SDS804X-HD.

It's more than you need right now, but it's amazing how quickly you can grow out of a tool once you realize its effectiveness.

It is also easily "improved" like most of the Siglent scopes.

It will eat the Owon for breakfast as an appetizer.

6

RF, Microwave, Ham Radio / Re: Fly swatter ham radio transmitter

« Last post by joeqsmith on Today at 02:26:27 am »

Housing for the aerial current and reflected power meters 

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Projects, Designs, and Technical Stuff / Re: Need help with Repairing a Sony Digital Paper Ereader

« Last post by Mantou85 on Today at 02:26:25 am »

Try different value resistors between the two white wires until you find something that clears the temperature error, you could start with 10k as suggested by Renate.
P.S. If you use, say a 50k pot you could adjust it to get the right resistance value.

Can you please translate this to a newbie? What type of device could I use to perform these tests.

8

Test Equipment / Re: SDS800X HD Wanted Features

« Last post by KungFuJosh on Today at 02:21:26 am »

wanted feature No.37

37? Yikes. I think you all need to decide on a top 10 most important feature request list. The longer your list gets, the less likely it is for anybody to look at it.

9

Beginners / How to reduce LED lamp DC powersupply voltage to power TV backlight LED's

« Last post by robsims on Today at 02:20:19 am »

Hi, i have a TV with a damaged powersupply board. The powersupply board doesn't output power to  the backlight LED's. I have a powersupply from a LED lamp that outputs 161 volts DC. I want to use this powersupply to power the LED backlights of the TV. The TV has 45 backlight LED's,  so the  voltage of one LED will be 161 : 45 = 3.6 Volts DC.  I want to lower the powersupply's 161 volts DC output so that every LED gets 3 Volts DC.  My quesion is what method can i use to lower the output voltage of the powersupply?

10

Metrology / Re: reading Keysight 3458A serial number

« Last post by TheSteve on Today at 02:16:35 am »

It doesn't count if it isn't running, needs to be 247.