Design of a Control Circuit

You have our heartfelt permission to proceed with your design.

Once you have designed the circuit you can post it here, if you'd like.

Or, perhaps you can search for such a design on the internet.

We won't do your homework for you here.

I have an app for that.....

Timer relays sounds like your best bet. Don't forget to follow your local wiring codes.

you have my approval, go ahead

Read about timers and relays, download the data-sheets of the ones that you might already have, they usually include typical applications, and make some experiments. As Redfred says, check the local wiring codes.

This method proves advantageous in many different fields, from powering a heater to complex equipment automation.

What codes? This is homework.

Yes!

Unfortunately, ethics has given way to expediency, even though almost all the information in the world is available with a simple search.

We see examples of that here many times each day.

It would be easier to list the legitimate requests for help than the requests such as this one.

Can you tell us what this heater is used for? Is this a product heater or a room/house/building heater? Or is this a first year project? If you can give me an acceptable answer that proves that this is not a homework assignment I/we may be able to help.

i have an autoclave in my hospital. the autoclave has two heaters each 2.5 kw. sometimes the nurses do not stop the autoclave in the right time which may damage the heaters. i want the autoclave to stop after certain time automatically and then an alarm start to alert the nurse to open the steam valve of the autoclave

If the alarm sounds for ten seconds and then shuts off, is it possible that it could do so without being heard/seen?

Is it possible that someone else, someone who did not hear the alarm, could start a new 30-minute cycle assuming the (first) had not yet been run?

A few ideas:

1. When the 30-minute cycle completes, sound the alarm as before. Use a visual alarm (a blinking light or whatever) as well as an audible alarm. Alarms do fail.

2. Sound the alarm continuously until it is manually reset.

3. Until the alarm is reset, electrically disallow a new cycle.

A 30 minute hourglass with a photo detector duct taped to one of the uprights. The amplifier to drive a relay of sufficient size to handle 5KW resistive at an unspecified voltage. The relay would also activate a solenoid valve releasing air from a balloon of sufficient size to maintain sound from a whistle or duck call for a period of 10 seconds.

I'm thinking Arduino or raspberry pi with a text alert

Here you go: A Minecraft redstone circuit.

You push the lever, power flows through the link at the end of the woodpile, de-asserting the inverter, removing power from the pistons, allowing lava to flow into the chamber, heating the big iron pot whilst igniting the woodpile, which acts a time-delay fuze. The woodpile burns to the end in approximately 30 minutes (29m 24.18s to be precise), breaking the redstone trace at the end, removing power from the inverter causing it to re-assert, re-energizing the pistons, shutting off the lava flow and playing the first eight notes of Westminster Quarters (the half-hour mark), which takes ten seconds, thanks to the repeater settings.

Here's your circuit. Takes about ten minutes to build.

See? That wasn't hard, was it?

But what if their using a quantum computer to drive this Minecraft redstone circuit. All iterations will be computed in just one step of the processor. This certainly should take less than 15 minutes, let alone 30 minutes.

They're using a Dell Perspiron running Minecraft v1.8pre3 under WinHozed 7 Homeless Edition. Nondeterministic (a la WinDoze), true, but not quantum.

Minecraft is pretty interesting. Cellular automata, done well. Like an ultra Conway's Game of Life, only much more sophisticated? Everything is based on blocks, even air. My youngest son learnt logic circuit principles from this program as well as "what are propagation and gate delays?", how to mitigate race conditions, and so forth. It's quite educational. My daughter got me hooked originally. She's a Minecraft fanatic (whereas Dad just dabbles in it). For her birthday last year I built her a huge underground world with over 120 km of working railways, a horse ranch (with about 1500 head and, if you pet them, they neigh when you approach them next time) and an ancient temple which, if you puzzle its dark secrets, opens an ancient, hidden wall to the Ender Realm where you have to fight a very, very nasty dragon.

Coal, silver, copper, zinc or iron mine? Good Luck, Old Salt

Salt.

Then what you need is Dr. Emmett Brown' s phone number. Great Scott!

there's this one

or this one you can make yourself!!

and failing all that thre is this one to which you can attach a horn or klaxton!!

I'd go for this one, as once the nurses have heard the alarm, they'll NEVER for get to switch off the autoclave!!

This is made more tricky by the possible consequences of the control circuit failing. Not too much problem if the heaters don't turn off after the 30mins - in the worst case the heaters may be damaged.

If, howerver, the circuit short-cycled, turning off the heat after say, 5 minutes, it could mean that unsterile instruments were unwittingly used on a patient - with a potentially very nasty outcome.

I agree 1000%.

Once I saw that medical safety protocols should be followed and that they weren't even recognized as relevant, I tried but failed to CMBM shut and watched who would and how they would respond to this delicate, seemingly simple question.

The instrument pack SHOULD include an indicator that 'tells' if sterilization is incomplete, or too wet. Does this no longer happen?

Jim

I have no idea whether docnagi uses instrument packs which include indicators. Or uses instrument packs (whatever they may be), for that matter. No idea where in the world he or she comes from.

He did say he was in a hospital so I ASSUMED that they were for operating/dental/clinic instruments. You are right, I should have stated my assumption. I learn something everyday on here. I guess that means I am alive.

Jim