Search found 1493 matches

by dyarker
Mon May 14, 2018 9:20 am
Forum: Projects & Kits
Topic: Would this 78SR-5/2-C work as a drop in replacement?
Replies: 3
Views: 1849

Re: Would this 78SR-5/2-C work as a drop in replacement?

You mean across the regulated 5V (to ground) before the display? Yes, but zener knee is not very sharpe. 6.xV or 7.xV would probably be better. Check the curves on the data sheets. You want 5.2V to be definately in the cutoff zone of the zener. (higher would defeat the purpose of using it though!) C...
by dyarker
Fri May 11, 2018 8:55 am
Forum: Projects & Kits
Topic: Would this 78SR-5/2-C work as a drop in replacement?
Replies: 3
Views: 1849

Re: Would this 78SR-5/2-C work as a drop in replacement?

Replacing one linear regulator with another linear regulator having higher max current rating solves part of the problem. But, heat (power) generated is the voltage drop across the regulator (not the output voltage) times the current. Increasing the current (even if still under max) requires a bigge...
by dyarker
Fri May 04, 2018 9:06 am
Forum: General Discussion
Topic: Typical 0.1 μF bypass capacitor value...
Replies: 4
Views: 1593

Re: Typical 0.1 μF bypass capacitor value...

Depends. Replacing a 0.1uF ceramic disk capacitor with a 1.0uf ceramic disk capacitor would be better. But, probably over-kill for not much improvement in performance, more expense, and more PCB space. Replacing a 0.0uF ceramic disk capacitor with a 1.0uF electrolytic capacitor could (repeat could) ...
by dyarker
Thu Mar 22, 2018 10:04 am
Forum: General Discussion
Topic: Security light motion sensors in parallel
Replies: 11
Views: 2216

Re: Security light motion sensors in parallel

sorry too! no downloads here (at my end), so haven't seen the diagram.
by dyarker
Thu Mar 22, 2018 8:30 am
Forum: General Discussion
Topic: Security light motion sensors in parallel
Replies: 11
Views: 2216

Re: Security light motion sensors in parallel

Didn't say fed from single circuit in post 1.
by dyarker
Thu Mar 22, 2018 4:53 am
Forum: General Discussion
Topic: Security light motion sensors in parallel
Replies: 11
Views: 2216

Re: Security light motion sensors in parallel

Do NOT connect the red wires (at least not yourself). They are switched AC hot leads. If AC to the detectors happens to come from different phases you'll at least pop a breaker. Even if you "get lucky" with the phases, one detector being on "bright" could damage the other as sghito said. It is possi...
by dyarker
Wed Feb 14, 2018 9:01 am
Forum: Computer Programming
Topic: web outlook mystery ( AKA Hotmail ? )
Replies: 4
Views: 812

Re: web outlook mystery ( AKA Hotmail ? )

Which is it, Outlook or Hotmail? Or, Outlook checking mail on a Hotmail account? Or2, do you mean Outlook.com, domain name for HotMail? Outlook is an e-mail client program by Microsoft (often part of MS Office). Hotmail is a web based e-mail service owned by Microsoft. "Outlook" and "AKA HotMail" do...
by dyarker
Thu Feb 08, 2018 4:17 pm
Forum: General Discussion
Topic: Detecting a magnet... from a distance.
Replies: 23
Views: 4670

Re: Detecting a magnet... from a distance.

In post 1 he said he wanted more posts on the forum.
by dyarker
Thu Feb 01, 2018 4:17 pm
Forum: General Discussion
Topic: Detecting a magnet... from a distance.
Replies: 23
Views: 4670

Re: Detecting a magnet... from a distance.

I recall rumor that ...
Not a rumor (that it could be done).
by dyarker
Tue Jan 23, 2018 7:06 am
Forum: General Discussion
Topic: i need some more Unobtainum...
Replies: 15
Views: 3237

Re: i need some more Unobtainum...

... so i am more than sure it is working ...
No, you are not. You're sure it is transmitting something. Has the carrier drifted outside what the receivers are tuned for? Is the ID code transmitted the correct one for that transmitter/receiver pair? Is the data being transmitted corupt?
by dyarker
Mon Jan 22, 2018 9:19 am
Forum: General Discussion
Topic: i need some more Unobtainum...
Replies: 15
Views: 3237

Re: i need some more Unobtainum...

???????????????????????????????? You replaced the receiver, still have a problem, and still say the transmitter is okay? Or did you mean you couldn't find a new receiver to buy? If the first case. the transmiter could be transmiting garbage. Cheers, P.S. A new non -rechargeable battery is 1.55V, so ...
by dyarker
Sun Jan 21, 2018 12:37 pm
Forum: General Discussion
Topic: Hammond die cast al case, heat sink?
Replies: 11
Views: 2678

Re: Hammond die cast al case, heat sink?

Can you calculate with Ohm's law? The thermal calculations are about the same. Temperature (degrees C) instead of voltage. Thermal resistance (degrees C per W) instead of Ohms. Power (Watts) instead of current (Amps).

But as you say, it is IMPOSSIBLE without the specs.

Cheers,
by dyarker
Mon Jan 15, 2018 4:52 am
Forum: General Discussion
Topic: Hammond die cast al case, heat sink?
Replies: 11
Views: 2678

Re: Hammond die cast al case, heat sink?

The pdf linked to in the original post is the spec sheet for all the cases in the model series. (as in many sizes)

There is no way to tell if a box (unknown) will be a good enough heatsink for a particular project without more info.
by dyarker
Sun Jan 14, 2018 8:43 am
Forum: General Discussion
Topic: Hammond die cast al case, heat sink?
Replies: 11
Views: 2678

Re: Hammond die cast al case, heat sink?

So, it sounds like you're saying the quality of aluminum is ok compared to the type of aluminum in a typical heat sink. I have no way to test the thermal conductivity of the aluminum, so ditto jwax. But I doubt Hammond purposely concocted thermo-insulating aluminum to make their boxes. I do believe...
by dyarker
Sat Jan 13, 2018 6:44 pm
Forum: General Discussion
Topic: Hammond die cast al case, heat sink?
Replies: 11
Views: 2678

Re: Hammond die cast al case, heat sink?

How much heat that can be "sunk" depends on outside surface area of the case. (not counting the area where it sits on the shelf or table)

Without fins the number Watts disappated will seem small for the size of the box.