prices for transistors just doesnt make sense - Page 1
Forum section: electronics / beginners

author: Capernicus
author_rank: Frequent Contributor
timestamp: October 14, 2021, 10:05:43 am
content: heres a 625mW transistor, thats millawatts, not megawatts, and its $2 power tranny hooker price.https://www.ebay.com.au/itm/362694300181?_trkparms=ispr%3D1&hash=item547243d215:g:vpIAAOSwxCVgFLdh&amdata=enc%3AAQAGAAACkPYe5NmHp%252B2JMhMi7yxGiTJkPrKr5t53CooMSQt2orsSlMTIifhgHFhC0bSIKdFeu1423czcae9rGX96hJnAoujoI%252F7Ja2uQX7NQsi4SJQe7VUGlzaRNIRYsEGXezbrsmmvWepL28Jv6%252B6afupVhEmOl9IU2MaOoFOZf9PJ%252Bvvq%252Fv8pK25AUJr9sl5gRPWUoXTnyyNasCperiX7Dr2Mgl8X8y92u8I0Kt4aka0YwGN6jG9jeTI8qroi3Y2kVdZQUT1v3OIgYbZWqavgPx9EnxGlrvNOOKdhdVESkfIyAQSiCxKsT9J89mwCzCM6HwaYIUfW9ZPi7WxIoixPdW7LQIrEy7Sa9gndqCSAjhzQZAVU4wWAZK1I8jn4rr62z7H0LyuWS163Pxn60q9GVtkbHDXiN7NGYzDRBTcH%252BQBxvp3hHCdeeLvDo37fP7weOuhqG2Qf68lAkLb3XK6G%252BIqbI2pqUwAF%252BZv9nsxSHCyBJ28FPFb5lMsvaf7ydwteduLKgJOCyRi4oFv6znvePgX2%252F%252B%252B3DlONblOKTKlcpojBhCL4LW8Cxe0yLQDf2NcgkePux7wfSWYDngFrp0nwZPPrM%252Bc7OartIY6zOfy6%252B%252FjdKzRsPi1IyD3aHuarFV%252F%252BNuPNLS3jhPqN3fPJ2Jkp6EqbOycSaTbfeiQ3l7xYGtnf1KYWXHSq9h7lkUrJF1naNh5NTJrCyi8Wxdk%252BGY4OMNYehBOhVitGLbkASegKKr6WvfQhaZY0u5frHY8GN4yrM214yb1jzCDPw8QthrHnK7OJDwb6MuxoGbVibDG6PxVZU5WEz%252FQAgw5mehgitTAUaWEr2MA5e1elg0dotg%252F%252Bzcp1%252BxveP134KgBzP5wuLmyt2tHTi%7Campid%3APL_CLK%7Cclp%3A2499334&var=631848582188Here is a 130 WATT!!!!! transistor $2 power tranny hooker price.https://au.element14.com/vishay/irl520pbf/mosfet-n-logic-to-220/dp/9102744?gclid=Cj0KCQjwqp-LBhDQARIsAO0a6aLHWPe39E2I-u3xiAaN9JggVLeXk6DKIiOhwrHz0iL9eiRmO7lhsEUaAreVEALw_wcB&mckv=_dc|pcrid|501152839127|pkw||pmt||slid||product|9102744|pgrid|123988903131|ptaid|pla-293946777986|&CMP=KNC-GAU-GEN-SMART-SHOPPINGThis doesnt make sense at all.<edit> hangon the link just changed, now it says its 50 watts, what a load of shit. </edit>

author: wraper
author_rank: Unknown
timestamp: October 14, 2021, 10:08:40 am
content: https://au.element14.com/multicomp-pro/2n3904/transistor-npn-to-92/dp/157437002?st=2n3904

author: wraper
author_rank: Unknown
timestamp: October 14, 2021, 10:10:40 am
content: Ebay price include free shipping BTW.

author: mikerj
author_rank: Super Contributor
timestamp: October 14, 2021, 10:13:41 am
content: You are comparing a small seller on eBay selling 2 parts at a time with free postage to a large international distributor likely selling hundreds of thousands of transistors every day, so this is hardly an apples to apples comparision.

author: tooki
author_rank: Super Contributor
timestamp: October 14, 2021, 10:36:03 am
content: Quote from: Capernicus on October 14, 2021, 10:05:43 amOh boy, here you go again trolling about what parts should and shouldn’t cost, despite clearly not knowing anything at all about what the differences between different parts and different vendors are.A 2N3904 transistor is, despite what that eBay listing says, not considered a power transistor. And that listing is a terrible price, since it’s essentially 100% shipping cost.The other, meanwhile, is a power MOSFET, a completely different beast.P.S. Duh, we all know that mW is milliwatts, since a) the prefix for mega is capital M, and b) megawatt power transistors do not exist. Megawatts is the scale of power for power plants, not components.

author: Capernicus
author_rank: Frequent Contributor
timestamp: October 14, 2021, 10:47:21 am
content: So how much does someone actually pay for a 30k watt transistor?and how much power is that exactly? I'm pretty sure you could move a car with that much power?

author: cgroen
author_rank: Unknown
timestamp: October 14, 2021, 11:05:33 am
content: Quote from: Capernicus on October 14, 2021, 10:47:21 amAnd I'm pretty sure you need to study a couple of books, 30 KW, it has to be a pretty big car with sticky tires if it would not move

author: Zero999
author_rank: Super Contributor
timestamp: October 14, 2021, 11:21:44 am
content: A car can be moved with under a hundred Watts, albeit very slowly.I don't think I've seen a 30kW power transistor. At multi-kW power levels, transistors are either on, or off. Linear mode is avoided, as it results in excess power wastage. Multiple transistors are used in series and parallel, to control large amounts of power. The power transistors, in inverter driving a motor, in an electric car, only dissipate a couple of kW at most. Most of the power is sent to the motors.

author: tooki
author_rank: Super Contributor
timestamp: October 14, 2021, 11:26:22 am
content: Quote from: Capernicus on October 14, 2021, 10:47:21 amI don’t know if 30kW ones exist. Buta 19kW IGBT is around $1800(USD).Bear in mind that the power rating of a transistor isn’t the amount of power that passes through it, but the amount of power lostinit that must be dissipated as heat.For example, a modern MOSFET with an on resistance of 40 milliohms could pass 20A of current at 50V (i.e. 1kW) and would still only dissipate 16W in the on state. (Dissipation would go up dramatically during switching.) Note that the voltage doesn’t affect losses, since the power dissipation is a function of current and resistance only. (Ploss= I2*R) So you wouldn’t need a 1kW MOSFET, maybe just a 20-100W or so unit, depending on how much switching it has to do.

author: Capernicus
author_rank: Frequent Contributor
timestamp: October 14, 2021, 11:40:49 am
content: IGBT MODULE 1200V 4930A - thats a million watts.Power - Max 19000 W ?? - only 19 thousand.Input Capacitance (Cies) @ Vce 225 nF @ 25 V. 225nf is fairly large and slow to fill.Makes me wonder what a million watt resistor looks like.https://www.ebg-resistors.com/en/products/ultra-high-power-resistors<- I had a look at these. but they are well off a million or even 20,000 watts.But you could beat the most ultra high power resistors in a mega high watt voltage divider, just with 2 ~1 picofarad capacitors (at the right ratio) and the right ac frequency (would be quite high), and it would generate 0 heat. any amount of power until the legs literally vaporize, it would still be going strong.costs 2c. 1c each cap.

author: tooki
author_rank: Super Contributor
timestamp: October 14, 2021, 11:55:38 am
content: Quote from: Capernicus on October 14, 2021, 11:40:49 amI literally explained that to you in the prior post, how you don’t need a 1kW device to carry 1kW of power. The watt rating of a transistor, resistor, etc is the amount of LOSS.The voltage and current ratings of a device are what its limits are, not how much power it can dissipate.Quote from: Capernicus on October 14, 2021, 11:40:49 amAnother pointless, unhinged proclamation.Quote from: Capernicus on October 14, 2021, 11:40:49 amI really don’t think you grasp just how big a megawatt of power is. A megawatt resistor likely doesn’t exist, because it’d be a) absolute insanity, and b) wouldn’t serve any sensible purpose. If your design requires the dissipation of a megawatt of heat, your design is inherently flawed.Quote from: Capernicus on October 14, 2021, 11:40:49 amAnd what do you think makes the legs vaporize? (Hint: it’s heat.) You still haven’t wrapped your head around the fact that real componentsalwayshave parasitic resistance, capacitance, and inductance. A capacitor that generates zero heat doesn’t exist. Sure, in typical application for small capacitances (like those of ceramics) the amount generated is so tiny as to not matter, but it is nonetheless nonzero.

author: Capernicus
author_rank: Frequent Contributor
timestamp: October 14, 2021, 12:12:55 pm
content: yes this high power rubbish, I think I better disband from it. maybe 90 watts is enough, more is just useless madness.They can make drag cars not even suitable for drag racing it just pointlessly powerful, and more dangerous. they make f1 carts go around corners at 100 kilometres an hour, how much faster do they need to be already.So this overpowered amplifier business is starting to scare me, I'm doing away with it, its how clever the sound is, not how loud it is.

author: tooki
author_rank: Super Contributor
timestamp: October 14, 2021, 12:30:31 pm
content: You have it backwards it: the wattage in a resistor or transistor is the loss, i.e.waste.You wouldn’t want a megawatt resistor because it means you’rewastinga megawatt of power (which is an enormous amount). You want the power tonotbe lost, so that it can go towards moving the car or making sound. So you’d design your system to have fewer losses.Let’s come back to my MOSFET example: 1kW load, 20A/50V.The 40mOhm MOSFET has 16W of loss. 1000W go in, 16W wasted, 984W left for the load. (So we use a 30W MOSFET.)Suppose we instead chose an older MOSFET with a 180mOhm resistance. The same 1kW load now means wasting 72W of power: 1000W go in, 72W wasted, only 928W left for the load. (So we choose a 100W MOSFET.)So the modern MOSFET that can “only” handle 30W is actuallysuperiorto the older one that can handle 100W.

author: DenzilPenberthy
author_rank: Frequent Contributor
timestamp: October 14, 2021, 12:36:37 pm
content: Quote from: Capernicus on October 14, 2021, 11:40:49 amI really don’t think you grasp just how big a megawatt of power is. A megawatt resistor likely doesn’t exist, because it’d be a) absolute insanity, and b) wouldn’t serve any sensible purpose. If your design requires the dissipation of a megawatt of heat, your design is inherently flawed.>1MW resitors are all over the place. Load banks for testing generators, dynamic braking resistors for train locomotives, etc etc.This is up to 4000hp which is around 3MWhttps://www.cressall.com/locomotive-testing/1MW:https://en.wikipedia.org/wiki/Load_bank#/media/File:Air_cooled_load_bank.jpghttps://en.wikipedia.org/wiki/Load_bank

author: Zero999
author_rank: Super Contributor
timestamp: October 14, 2021, 12:40:15 pm
content: Quote from: Capernicus on October 14, 2021, 12:12:55 pmPerhaps a mechanical analogy will be easier to understand.Suppose you have a super-car, with an engine capable of outputting 500kW. The clutch controls whether the engine is connected to the drive chain or not. This doesn't mean the clutch is capable of dissipating 500kW. It will be able to safely dissipate a tiny fraction of that, for a short length of time, before burning out.The same is true for a transistor controlling a load such as a motor. Like the clutch in a mechanical transmission, it only acts as a switch. The power dissipated by the transistor is minimal.

author: Capernicus
author_rank: Frequent Contributor
timestamp: October 14, 2021, 12:49:41 pm
content: So is it the clutch resisting the movement of the diff? is what it is dissipating?

author: tooki
author_rank: Super Contributor
timestamp: October 14, 2021, 01:05:01 pm
content: Quote from: DenzilPenberthy on October 14, 2021, 12:36:37 pmFair enough, I didn’t even think about artificial loads!With that said, the discussion so far has been about components; a load bank is literally a bank of indivual components. The 4000hp/3.1MW load bank above says it uses 12 resistors, so about 260kW each.And of course, the main point (being that you don’t really want toneedsuch parts in a design) stands, other than in artificial loads of course.

author: tooki
author_rank: Super Contributor
timestamp: October 14, 2021, 01:08:46 pm
content: Quote from: Zero999 on October 14, 2021, 12:40:15 pmThat’s a great analogy!(Not sure if he understands what a clutch does, how it works, or what “dissipation” means, though, based on the reply…)

author: tooki
author_rank: Super Contributor
timestamp: October 14, 2021, 01:12:32 pm
content: Quote from: Capernicus on October 14, 2021, 12:49:41 pmDo you understand what losses are? (Be they electrical or mechanical energy, physical product, etc) (Not a criticism, just a question. Your responses in many threads indicate to me that there are some fundamentals that you don’t really understand yet, and that’s making it hard for you to understand the answers people give you to your questions.)

author: Capernicus
author_rank: Frequent Contributor
timestamp: October 14, 2021, 01:14:06 pm
content: sorry I missed it. so thats a massive resistor? they get damn uselessly big, thats the problem. You only need that much power if your going to power some collosus destroyer, but its just utter madness, you dont need one of those things at all.

author: cgroen
author_rank: Unknown
timestamp: October 14, 2021, 01:18:13 pm
content: Quote from: cgroen on October 14, 2021, 11:05:33 amI still stand with what I wrote previously....You really need to learn the basics before analyzing prices of semiconductors.....

author: tooki
author_rank: Super Contributor
timestamp: October 14, 2021, 01:20:22 pm
content: Quote from: Capernicus on October 14, 2021, 01:14:06 pmYou don’t power anythingfromthem. You use them toburn up power coming from something else.

author: Capernicus
author_rank: Frequent Contributor
timestamp: October 14, 2021, 01:25:32 pm
content: you combine resistors with transistors and it makes them work better. if u need to invert a transistor, u need a resistor, if you need to delay, u need a cap, this is ordinary stuff. i do alot wierder things with them.

author: Zero999
author_rank: Super Contributor
timestamp: October 14, 2021, 01:26:32 pm
content: Quote from: Capernicus on October 14, 2021, 12:49:41 pmI'm not sure if I understand the question.The clutch simply controls whether the gearbox is connected to the wheels. It only dissipates a significant amount of power, when it's slipping, which is when the car is moving very slowly, or starting to move. It acts like a switch.

author: rstofer
author_rank: Super Contributor
timestamp: October 14, 2021, 02:15:27 pm
content: Quote from: tooki on October 14, 2021, 11:55:38 amIn a way MW size resistors do exist. Nuclear fuel bundles (around 100 3/8" diameter tubes usually filled with nuclear fuel in the form of pellets) are tested for consistency of the boiling point level. The tubes are filled with a thermal material to mimic the fuel pellets and current is passed through the bundle, top to bottom. A LOT of current... Think in terms of 20 MW! We want the water to turn to steam at a consistent level across all of the tubes.The tube bundle is just a big resistor and it dissipates a LOT of heat!The test doesn't last long so the kWh isn't all that expensive but the kW demand charge is a killer! Sometimes the test ran at 20 MW!See Figure 6 for BWR fuel bundle.https://world-nuclear.org/information-library/nuclear-fuel-cycle/conversion-enrichment-and-fabrication/fuel-fabrication.aspx

author: tooki
author_rank: Super Contributor
timestamp: October 14, 2021, 02:17:27 pm
content: I suppose so. But like the load banks and track resistors, that is an application well afield of electronics. Even calling those “power electronics” is a stretch.

author: tooki
author_rank: Super Contributor
timestamp: October 14, 2021, 02:22:13 pm
content: Quote from: Capernicus on October 14, 2021, 01:25:32 pmKinda sorta. “Work better” is certainly not how I’d word it.Nonetheless, do you understand that, say, if you were making a power supply capable of supplying a megawatt, that thisdoesn’tmean you’d be using megawatt resistors to build it??Do you understand the example I have with the MOSFETs? Yes or no, simple question.

author: rstofer
author_rank: Super Contributor
timestamp: October 14, 2021, 02:22:42 pm
content: Quote from: Zero999 on October 14, 2021, 11:21:44 amThe DC motor in the Chevy Bolt is 149 kW or 200 HP. The thing is, the lag between throttle off and full power is nearly instantaneous. The gasoline engine doesn't come up to full horsepower until the RPM is near max. The Bolt can be quite sporty!

author: rstofer
author_rank: Super Contributor
timestamp: October 14, 2021, 02:26:35 pm
content: Quote from: tooki on October 14, 2021, 02:17:27 pmMy fuel rod example above was phase angle fired IGBTs in a tightly controlled PID loop. There were actually 2 parallel locomotive drives controlled by the test platform. Mostly electrical but definitely electronic control.

author: Capernicus
author_rank: Frequent Contributor
timestamp: October 14, 2021, 02:33:04 pm
content: Quote from: tooki on October 14, 2021, 02:22:13 pmI dont know exactly, so I'm down a few points there. But I know that low resistances heat up more than high resistances with the same wattage, and not all your power is going down the whole thing, Alot of the time I end up with 1 fried resistor and the rest are ok.But I think I'm missing a piece of knowledge here to answer your question properly.

author: TimFox
author_rank: Super Contributor
timestamp: October 14, 2021, 02:52:01 pm
content: At my previous employer, we bought a custom precision linear power supply from Danfysik (in Denmark) to supply 250 A into a 1 ohm electromagnet load (250 V) for 62.5 kW output power. (They used one of their DCCTs to achieve better than 1 ppm stabilization.). The pass transistor used maybe 100 2N3772 TO-3 NPNs on a water-cooled plate. The pre-regulator was a servo-controlled variac ahead of the rectifier to keep theVCEat a few volts. Each transistor had a fuse in the emitter, and an interlock to allow operation with less than 10% of the transistors failed.It was expensive.

author: TimFox
author_rank: Super Contributor
timestamp: October 14, 2021, 02:54:39 pm
content: Quote from: Capernicus on October 14, 2021, 02:33:04 pmWhy do you say that low resistance resistors heat up more than high restancesat the same power? That is true (all other things equal)at the same voltage, not power.

author: dmills
author_rank: Super Contributor
timestamp: October 14, 2021, 03:01:37 pm
content: Quote from: TimFox on October 14, 2021, 02:52:01 pmDistinct shades of old school ion laser power supplies, dozens of '3055s on a water cooled plate.Trouble with those was always that the electronics was installed on a board below the cold plate, so when you shut down and the chilled water drove the cold plate below the dew point...Yea made some decent bank back in the day rebuilding those things.

author: tooki
author_rank: Super Contributor
timestamp: October 14, 2021, 03:09:24 pm
content: Quote from: Capernicus on October 14, 2021, 02:33:04 pmThank you, now we’re getting somewhere. Remember, nobody here is trying to embarrass you or anything. But you did need to stop acting as if you understand everything, and coming in making grand claims about things you don’t actually understand.Every single one of us here was a total beginner at some point, and gained knowledge over time. You will too and people here will help!Your observations about resistors are partly correct. The wattage of a resistor is simply how much heat it can tolerate before it burns up. That’s independent of the value as such.You sorta correct that, with voltage (not power!) held equal, a resistor of lower resistance will heat up more than one with a higher resistance. This is Ohm’s Law at work: as the voltage “pushes” current through the resistor, the lower resistance allows more current to flow, but also means a larger voltage drop. The larger current, according to the formula I gave earlier (Ploss=I2R)*, means more heat.A higher value (resistance) resistor will heat up just as much, it just takes a higher voltage to do it. For example, 1A through a 10 ohm resistor, or 0.1A through a 1000 ohm resistor, both dissipate 10W. Within a product line, both of those resistors would be the same size and appearance, though their internal construction would differ. (And the voltages would differ: the voltage across the 10 ohm resistor would be 10V, while it’d be 100V across the 1000 ohm resistor.)In a voltage divider, the voltage gets divided up proportionally among the resistors, as you know. The current, however, may not be the same across the branches of the divider. Since current is what causes the heating, the differing amounts of current through different branches is how you’ve ended up with some resistors fried and others fine.That’s a great observation. The key now is to understand why and how it happens.*this is known as Ohm’s power law. Ploss=I2R is basically shorthand for Ploss=V*I, referring not to the supply voltage, but to the voltage drop across the resistor. But to calculate the voltage drop is I*R, so we just substitute that into the formula, giving I*R*I, or I2R.

author: Capernicus
author_rank: Frequent Contributor
timestamp: October 14, 2021, 04:00:27 pm
content: There is no voltage drop across a resistor, otherwise capacitors wouldnt even charge with a resistor in front of them. how the hell would it ever equalize with the power supply if that was true.But the high value resistor seems to die at a lower amount of amps than the low value resistor, and thats what I initially thought would happen, because the low value resistor affects the value less, so it wont heat up as much.BUT!Nonintuitability strikes again, and its the LOW VALUE resistor that takes the heat, not the high value.So I guess you guys are experts at making toaster ovens. And that can help a great deal for more fancier technology as well, like nuclear reactors for example.What about constant current circuits, the amount of current is now the OPPOSITE of what the resistance is with a raw connection, the lower the resistor the less current is there, and the more resistance the more current. thats going to trick people when they read your circuit! youll have to apologize for everything being backwards because it just had end being that way when everything ended up working.But, I have a gift for u dudes, perhaps something you do not know yet, as I thank you for bringing me up to speed on the wattage heat issue, and its the fact that a resistor will not oppose any current until enough current has tried to force its way through it, otherwise it will go through unaffected by the tighter pipe.

author: rstofer
author_rank: Super Contributor
timestamp: October 14, 2021, 04:32:24 pm
content: Quote from: Capernicus on October 14, 2021, 04:00:27 pmThat claim contradicts Ohm's Law and it is a LAW; you can't treat it like a speed limit.E = I * RI = E / RR = E / IThese 3 equalities hold.P = I * EP = I2* RP = E2/ RThese Power equalities also hold.E in VoltsI in AmpsR in OhmsP in Watts

author: Capernicus
author_rank: Frequent Contributor
timestamp: October 14, 2021, 04:39:42 pm
content: But what if your supplying less current via PWM.Im talking about loadless resistance, a lack of amps.Another way Ohms Law doesnt hold is when the battery is out of omph, like during a short, and it hasnt enough energy in it to fill the entire circuit, least resistance gets it all. high resistance misses out.Ohms law only holds for an ideal infinite power source.Increasing the volts, without increasing the amps, the same thing.

author: Manul
author_rank: Super Contributor
timestamp: October 14, 2021, 05:04:15 pm
content: Sadly, I think it's a case of a CPU core running under induced brownout.

author: TimFox
author_rank: Super Contributor
timestamp: October 14, 2021, 05:28:27 pm
content: A resistor (a block with two leads) doesn’t know what the external circuit is: it only knows the current through it and the voltage across it. The ratio is the resistance (Ohm’s Law) and the product is the power dissipated in it. “Voltage drop” is another term for the voltage across the resistor, which is the voltage between the two leads (whether wires, surface-mount terminations, or other terminals).

author: Capernicus
author_rank: Frequent Contributor
timestamp: October 14, 2021, 05:30:51 pm
content: I don't trust the voltmetre. I think it reads lies, I'm always careful when I look at that thing suspiciously and watch out for the electric shocks at the same time.

author: rstofer
author_rank: Super Contributor
timestamp: October 14, 2021, 05:35:21 pm
content: Quote from: Capernicus on October 14, 2021, 04:39:42 pmNorton's Theorem and Thevenin's Theorem explain all we need to know about internal resistance.When we say E = I * R, we include ALL of the R in the circuit including the source output resistance.The current goes down all of the branches in proportion to their resistance. It you have 10 Ohms in parallel with 100 Ohms, you can expect the current through the 10 Ohm resistor to be 10 times the current through the 100 Ohm resistor. That's because the same voltage is across each resistor.E = I * RE = 1V <= identical arbitrary voltage across each resistor1V = 0.1A * 10 Ohms <= the current through the 10 Ohm resistor (0.1 Amps)1V = 0.01A * 100 Ohms <= the current through the 100 Ohm resistor (0.01 Amps)You seriously need to take a DC Circuits class.

author: rstofer
author_rank: Super Contributor
timestamp: October 14, 2021, 05:39:36 pm
content: Quote from: Capernicus on October 14, 2021, 04:39:42 pmSo what? You do an RMS calculation on the PWM duty cycle and use that value for E. You will get IRMSfor whatever resistance you use in E=I*RQuoteIn which case you are talking about 0 Volts. Ohm's Law does hold, you just need to include all the resistance.QuoteFor a given resistance, you can't increase the volts without increasing the amps. Ohm's Law ALWAYS holds! That's why it is a LAW, not a suggestion.

author: Capernicus
author_rank: Frequent Contributor
timestamp: October 14, 2021, 05:45:51 pm
content: So. let me draw a picture...................................-(neg)...........................................................................|.....................................|.....................................|..+(pos) -/switch --100r-----100r--- +(pos)ok so heres a couple of 100r's with a switch on the left side.I'm guessing that you guys think that when that switch closes, the absolute resistance drops given the two lines and more is asked of the battery to fill those lines.And the battery will always have this power.This is the flaw.Sometimes, the battery hasnt got the PEAK OUTPUT required to fill both the lines. or if its a capacitor, it simply runs out. and then something happens, the resistance becomes relative.Now, youll get two lines with half the current each, and it will use the ratio of the two resistances.If it so happened to be this->..................................-(neg)...........................................................................|.....................................|.....................................|..+(pos) -/switch --1r---------100r--- +(pos)now there is alot less resistance on the switch.When this baby closes theres not enough power on jupiter to even run that line alone, and the line with the resistor actually gets NILL current completely.The smaller the battery you use, the less absolute resistance is obeyed by the system, and the resistors are now seen in a relative speed to each other, who gobbles up the current first gets it all.If you deliver a 1% PWM ratio to a circuit, with a big long gap, this short pulse of energy (Which can actually be any amount of amps, if its a very sharp loud pulse.)Will be eaten up by the least resistance first, and the higher resistance lines are so slow, they miss out on it completely.The less amps given to the circuit, the more relative the resistance becomes.The extreme end of this, is a 1 ohm resistor can actually pass equal current to a 10k resistor, if there isnt much supplied. yes, the 1ohm resistor gets it alot quicker, but it just shoots through it like lightning with nothing after, the 10k resistor, being slow as it is, if its still able to contain that amount of current till the next pulse, will the pass the same amount of amps as the 1ohm, but it goes through smoothly continuously over time.Amazin' eh?How the circuit is powered, is just as important as what the circuit is.You can increase the volts without increasing the amps, its what transformers do.

author: TimFox
author_rank: Super Contributor
timestamp: October 14, 2021, 05:45:58 pm
content: "Ohms law only holds for an ideal infinite power source."No.

author: rstofer
author_rank: Super Contributor
timestamp: October 14, 2021, 05:53:17 pm
content: I hope a noob never sees this thread! It will set them back decades in their understanding of circuits.

author: tooki
author_rank: Super Contributor
timestamp: October 14, 2021, 05:58:35 pm
content: Quote from: Capernicus on October 14, 2021, 04:00:27 pmOh, honey… you need to shush before you make yourself look silly!Voltage drop is real, and easily measured. It’s how voltage dividers work. And of course a cap can charge via a resistor (and remember, since everything has parasitic resistance, every capdoescharge and discharge through a resistance). Look up RC time constants…I understand where you’re coming from regarding resistance vs heating; as a kid, I intuitively expected the same. But once I learned more, I learned how the opposite is the case. Heating is the result of current and resistance, and a lower resistance allows more current to flow. It’s that simple. I’ve explained it to you twice.You have no idea what a constant current circuit is.I’m coming to realize that I don’t think you actually understand what current is.Your “gift” is random electrical words put near each other. They don’t make any sense as a whole.Quote from: Capernicus on October 14, 2021, 04:39:42 pmComplete and utter nonsense.Quote from: Capernicus on October 14, 2021, 05:45:51 pmMore complete and utter nonsense.

author: Capernicus
author_rank: Frequent Contributor
timestamp: October 14, 2021, 06:15:29 pm
content: If you count the off periods of the PWM as infinite resistance maybe it holds true to ohms law, I haven't thought about it yet.It's funny that you guys dont believe in me, But boy do I believe in myself!!!I've been a little slow, and its actually been about 5 years, and I haven't finished an oscillator yet, but when I get it, I'm not going to be average and just leave it there as a set of christmas lights, I'm going all the way to a full pipelined asic. Its going to be great.Its actually not that hard, a ttl pipelined asic is doable by anyone, especially with fpga experience. you can get the whole machine plotted tiny little and gates, im sure you can fit 10,000 on a pcb one sided, but I dont want to buy parts for my stuff.I'm going to do all my design in open-scad, circuit, bodywork, everything, my favorite CAD software, because I've been coding for a good 17 or so years now, and I am going to fire into hardware, frizzly resistorz. And script modelling is good for people that have been pretty much typing more lines ever since being an insubbordinate student in primary school.https://openscad.org/<-decent program.And im going to undercut china single handed.But sillyness aside, I think china or anyone else dont really care, theyve got all their own technology as well... but I'm gonna kickass for the OZZIES.

author: tooki
author_rank: Super Contributor
timestamp: October 14, 2021, 06:25:30 pm
content: Quote from: Capernicus on October 14, 2021, 06:15:29 pmClearly. I’m skeptical about the “yet” part, as that implies it might happen later.Quote from: Capernicus on October 14, 2021, 06:15:29 pmI can’t imagine why…Quote from: Capernicus on October 14, 2021, 06:15:29 pmThat much is evident. The unfounded confidence is… impressive!

author: Simon
author_rank: Unknown
timestamp: October 14, 2021, 06:52:27 pm
content: Quote from: Capernicus on October 14, 2021, 10:47:21 amSounds like you don't really know what you are talking about. what was the purpose of this thread again? Yea right now stuff is expensive, it's called supply and demand. As already pointed out 2 parts sold on ebay with free shipping is no comparison to a mainstream distributor, guess where the ebay seller get's them from. I did it too once, made a nice bit on the side!