Garage Door Opener

Sorry, but this is cute!

Herz please can you explain this comment? I don't know what you mean.

Sorry, Hurz.

It means he is is a cocky big mouth that thinks he is so great with his little circuits. Oh good for u hurtz, ur so salty and experienced so make sure to put everyone one else down to compensate ur little man complex.

@gonzo, is this your only bullshit reference? http://everycircuit.com/circuit/4608164141465600

Fuck u hurtz. You think ur so smart and clever because u know so much about circuits? Good for u but you know what? You're still and always will be a little insecure man that gets his kicks by spending all his time on this application. Get a life you loser. I dont claim to be an expert with this stuff but its a hobby and im learning. Your nothing more than a simple insecure person that gets off on your knowledge which i doubt is even yours. Most likely you steal ideas off the web based on ur personality you putz. I will say one thing, if ever ran into in person, i would love to push your face in

You seems to be a frustrated troll.

No, you're an insecure asshole that needs your face pushed in.

Gonzo the Great, i love your stunt performance!

Oh is tiny shrivled old fart loving that i am not kissing your ass like some of your disciples on this app. Ooooo, you made a circuit that can make ur signature, good for you. Anybody can get good at something sitting around doing it all day. Why dont you get out of your basement and go get laid........oh thats right, ur too busy building circuits and looking for acceptance and a pat on the back from this app community.

Gonzo the Great, are you jealous? What can you do best, being frustrated, playing with dynamit, using low level vocabular? Im very impressed.

I know one thing. I am secure with my life and what i do for a living that i dont need to get my rocks off and get reassurance from people on some app. I am on here to learn things and not be ridiculed by some german asshole thinking he's better than everyone else.

Okay I just posted a circuit. What's going on here haha

I like your circuit and the comments are entertaining.

Come on Hurz. What does your comment on the circuit mean? Grow some balls and answer the question.

Colezilla74, you are a star!!!!

Hurz as and Englishman I can tell you that your English is far, far from perfect. However, it is infinity better than my German. The difference is that I'm prepared to own up to my weaknesses but you are never wrong. Try being honest. There are many people on this site that (rightly) respect your electronics knowledge. But, as a human being your attitude stinks. I'd be prepared to offer friendship but you don't seem to want or need it. You could be smart & liked. Think about it.

Looks a bit 'over engineered' to me. What about replacing the LED in the following circuit with your relais: http://everycircuit.com/circuit/5355705678168064/switch-delay

You can't drive a 1kW load with a transistor. You need a power relay, and they need to be driven by either a powerful transistor or another less powerful relay, and the latter is more feasible

Wasn't cue108 suggesting that his simple circuit could feed your first relay (11.9mA) instead of having to use your 'over engineered' circuitry to do that?

Ah, then no, the op amp is probably necessary, because the human skin resistance varies and may be up to several hundred kOhm, and the circuit was designed to work by shorting two metal plates with your fingers.

Also you can control the threshold level with the 100ohm emitter resistor, and with his circuit the threshold is quite low at around the Vbeo voltage of the transistor

Right on, however, I seem to remember messing on a breadboard a long time ago with switching a transistor or two (or a mosfet or thyristor) with a light finger touch and pot for sensitivity before I even got into opamps ... I am not decrying opamp usage, but is that opamp plus extra transistors a bit of overkill? I am not contradicting, I am just wondering.

@thebugger finger control: replace the switch in my circuit with an n-channel MOSFET's drain and source pin with 1 MOhm resistor from gate to GND and having your metal plates between Vcc and Gate.

@Thebugger you could also replace the relais with a high side n-channel MOSFET switch involving a photovoltaik opto coupler as the high side driver. You can buy MOSFETS with 65A and 600V Drain to Source characteristics for under 3$ a piece. They could then switch 600V times 65A = 39kW. That should be enough for every door to open!

@Thebugger just for you: 400V 8.5A continues Drain to source current = 220V * 8.5A = 1.8kW http://www.irf.com/product-info/datasheets/data/irfy340c.pdf

Op amps are more sensitive and accurate and as for the transistor relay choice, well the transistor you propose wouls dissipate 11W of power and that'll require a considerably big heatsink or else the qualities will derate quickly. Anyway heavy loads are rarely handled by transistors, mostly relays and thyristors.

P.S. You're not reading the dataheets right. You must look at the maximum dissipation and the internal resistance as well, not just the maximum ratings. For instance the maximum dissipation of this transistor is given as 60W and the internal resiatance at 0.55ohm. At 39A you'll be dropping 21.5V across it. When you multiply those two you get a power dissipation of 830W, just by the transistor. That's waaaay off the maximum rating

@thebugger As I am new to the EC app and still so excited about the prototyping speed with it, I enhanced my initial circuit to deliver an example for you. http://everycircuit.com/circuit/5355705678168064

@thebugger I think you mix something up with the maximum power dissipation versus the power transmission. I will explain: given are 0.55Ohm Drain-to-Source on state resistance at 5.5A and Vgs 10V. In your application 1kW load are reached by 1kW/220V=4.54A. With 0.55Ohm Drain-to-Source at 4.54A you will need to dissipate 4.54A^2*0.55Ohm = 11.34W. No Problem!

The heat think you would need with a single irfy340c would be this one. http://www.digikey.com/product-detail/en/aavid-thermalloy/529901B02500G/529901B02500G-ND/1625167 But you could also take either two of those MOSFETS in parallel coupled over a smaller Heatsink or take another MOSFET. The one I provided was just my first click..

I really appreciate our little talk! I found another MOSFET for you. https://www.fairchildsemi.com/datasheets/FQ/FQP22N30.pdf 160 mOhm @ 10.5A, 10V 4.54A^2*0.16Ohm=3.3W power dissipation. That should be ok and the price per peace is $1.98.

http://www.digikey.com/product-detail/en/fairchild-semiconductor/FQP22N30/FQP22N30-ND/1056856

Yes and a relay dissipates no heat and can provide galvanic separation, which ia desirable

Galvanic separation is a reasonable argument. Thus look at this: http://www.avagotech.com/products/optocouplers/industrial-plastic/other/solid-state-relay/assr-v622-002e Since these opto isolators are voltage source themselves its an independent high side n-channel driver. Just awesome if you know about charge pump driven high side drivers. Relais: mechanical parts, big and somehow obsolete in my opinion.

I used to think like that, and when I said it to my teacher, he was going to slap me. Relays have immense applications even nowadays. Every component in your car is driven by a relay, every residential building has the elevator and lights driven by a relay. They're not that obsolete. Neither are tubes. To be honest tubes are my favorite components, and I like to work with them very much. I've been shocked a few times, but that's a rite of passage for every future engineer :D

P.S. Solid state relays are still transistors, but are driven by light, and have the same limitations as normal transistors. They can't work with AC so easily, they dissipate heat, and are somewhat inefficient at high currents, when compared to relays. IGBT's look promising though. They have the huge gate impedance of MOSFETs and the high current capabilities of a well driven BJT. The few limitations of relays are the slow speed of switching, and the fast wear-out in comparison with other components, but when maintained appropriately, they should have a long life.

Rite of passage.....When I did my electrical apprenticeship we learned to do all the wiring and conduit etc at first on a long bench using only low voltage. When we knew it all it was changed to full 240v mains. One day soon after, I leant on the conduit with my hand and got a massive shock (doubt my heart would take that now)...one of my workmates must have wired it wrongly. I turned to my mates (with unsurprising language) and said 'Did you see that ...I just touched the conduit like this.....', and repeated the procedure and got another shock!... Such was my stupidity....some may have noticed that I still have a good measure of it.

The trick is to not get shocked between hands. In between fingers it's ok. I learned to keep one hand behind my back while working with HV

Sorry Bugzy, but I gotta say 'turn off the power before examining a circuit with any significant voltage present or charged capacitor!" LOL. I did once make a mains extension lead - actually 2 leads in fact. Because of the awkward route it had to take I realised I could get more effective length by having 2 plugs on one cable and two sockets on the other. Duh! I had the plug inserted into the mains outlet, then casually picked up the other plug and received the only electric shock I've ever had (so far). Not my finest hour!

Although I would always prefer not to use a relay there are some instances where they really are the best choice.

Well I don't know what your deal with relays is, but I never omit them whenever I can use them. They have quite a few advantages over other types of switches. They are more robust, can withstand arcing and reverse voltages, as one might expect from motors, offer galvanic separation and are more efficient than transistors. The disadvantages are slow speed and short life, although with proper maintenance they could probably outlive transistors in the same application. There are some applications, where they should be avoided though. I particularly don't recommend them with filament loads, because they wear the contacts very quickly, where semiconductors can easily withstand high peak currents, that are magnitudes of order, larger than the continuous capabilities of the device, without failing. So to sum it up, and probably close the subject, I'd say I always use relays when they're required, without trying to substitute them for semiconductors, but whenever I see problems, from using a relay, I don't think twice about using a semiconductor. It's all about pros and cons in specific situations