Home Community

Recent Posts

Recent Posts

Pages: [1] 2 3 ... 10
1
Service Manuals / Re: cyberpower 375SL service manual?
« Last post by abador on Today at 01:23:03 AM »
I cracked the unit open and checked the voltage at the battery with the unit unplugged and then with it plugged in. Unplugged it reads under a volt but when it is plugged in the circuit reads 13 volts. I figure this means the charging circuit must be good but the battery is bad. The battery is a 12 volt battery. I am pretty certain that the battery is bad but could this cause it to keep switching on and off when the unit is plugged back in? Also I'm pretty sure it is lead-acid.
2
Service Manuals / Re: cyberpower 375SL service manual?
« Last post by audioguru on October 29, 2014, 06:51:17 PM »
I agree that the battery might be bad.
If it is lead-acid or Lithium then its life might be finished. Replace it.
3
Electronic Projects Design/Ideas / Re: Can I use a common ground
« Last post by audioguru on October 28, 2014, 06:39:57 PM »
Its datasheet says the relay is a Chinese "Songle" relay. What is that?? They cannot spell "single"?
Its coil current is 120mA at 3V.

I betcha the sensor cannot provide an output current as high as 120mA at 3V. Then the relay needs a transistor to drive it and the sensor drives the transistor.

Instead of a transistor and a high current relay why don't you use a low input current darlington transistor to drive the sprinkler?
4
Electronic Projects Design/Ideas / Re: Can I use a common ground
« Last post by nzdavo on October 28, 2014, 04:22:27 PM »
Hello Audioguru

Thank you for your reply.
I launched into this with little more than my high school electronics memories so please excuse my noobness!

The coil voltage is 3v. The relay is a songle srd-03vdc-sl-c  (Datasheet here - http://www.ic-on-line.cn/view_download.php?id=1824874&file=0413\srd-03vdc-sl-c_4766638.pdf)
I will measure the current of the sensor output tonight.

The sensor requires 12V in and the solenoid also requires 12V but the output from the sensor is 3V so I thought the relay would be a good work around. (Was I right?)
I wired it up (with alligator clips) and used my multimeter to check the voltages. I get 3V from the sensor only when it's not grounded. (Multimeter probes on the 3V output and 12V ground)
I also tried two AA batteries in series (giving 3V) and attached that to the coil. It worked like a charm. (The relay switched and allowed 12V to pass through to the solenoid.)
So I think it appears that I have a grounding issue with the 3V output.... and it also appears that I am in way over my head!

Cheers
David

 
5
Service Manuals / cyberpower 375SL service manual?
« Last post by abador on October 28, 2014, 01:56:15 PM »
I bought this battery backup system from a thrift store for $4.99 hoping to have something that I can use to power some important items when the power goes out. once I got it home I charged the battery for more than the recommended 8 hours and the battery still does not kick in when I unplug the device. Also when I plug the system back in it starts turning on and off until I remove the load from the battery plugs. Does anyone have any idea what could be wrong with it? There is a label on the outside stating that there are no serviceable parts inside but I assume I might be able to solder and unsolder stuff to the circuit board. Also if someone can find a service manual that would be very helpful.
6
Electronic Projects Design/Ideas / Re: Can I use a common ground
« Last post by audioguru on October 28, 2014, 01:06:46 PM »
You did not provide the coil voltage and its current of the relay and did not provide the output current of the sensor when its voltage is only 3V.

The coil produces a voltage spike of hundreds of volts when the relay turns off. Usually a reverse-biased diode is connected parallel to the coil to prevent the spike.
7
Electronic Projects Design/Ideas / Can I use a common ground
« Last post by nzdavo on October 28, 2014, 05:32:40 AM »
Hello All

We have been having issues with neighbourhood cats so I decided to cobble a cat sprinkler together. I have purchased a solenoid valve, infrared sensor and a relay.

Please see my diagram attached.

The Infrared sensor requires 12V but the output is only 3V. The solenoid valve requires 12V so I thought a relay would be needed. However I can't seem to get the circuit to work off a single 12v power supply. I have 12v running to the sensor and the relay. These both share the same ground and that seems to work ok. Then I have 3V coming out of the sensor and into the coil on the relay. I want to send the negative (Highlighted in purple) to the same ground as the rest but this isn't working. If I use a separate 3v supply the whole thing works. Can anyone tell me what I am doing wrong?

I hope I have explained that properly!

Thank you for your help.

Kind Regards
David

8
Projects Q/A / Re: Power supply short circuit protection.
« Last post by sbrutfl on October 27, 2014, 03:53:35 AM »
Anyway, does someone know an effective way to protect this power supply from the short circuit?
The corrected latest version reliably regulates the maximum current to be 3.0A. Then an additional protection circuit is not needed.

Buy name-brand parts from an honest electronic parts distributor, not cheap fake junk from ebay and the project will work fine.

Good, thank you very much for your help :)
9
Projects Q/A / Re: Power supply short circuit protection.
« Last post by audioguru on October 26, 2014, 10:46:36 PM »
Anyway, does someone know an effective way to protect this power supply from the short circuit?
The corrected latest version reliably regulates the maximum current to be 3.0A. Then an additional protection circuit is not needed.

Buy name-brand parts from an honest electronic parts distributor, not cheap fake junk from ebay and the project will work fine.
10
Projects Q/A / Re: Power supply short circuit protection.
« Last post by sbrutfl on October 26, 2014, 02:01:54 PM »
It's a new anti-spam measure.  Once you hit a certain post level you'll be able to post links.  I've tested this with a setup of SMF I had going for awhile to see if it worked and would be a good fit here.  I think if you keep the http and www off of the link you should be able to avoid the spaces like I did with it in the above quote.

Oh, ok, no problem then :)

Anyway, does someone know an effective way to protect this power supply from the short circuit?

Pages: [1] 2 3 ... 10