Breaking news coverage for car buyers and auto enthusiasts with spy shots, reviews, auto shows, offbeat stories and more at Carscoops. we had this same issue starting this morning and goti it solved hope this helps SSL on IIS 8. Everything was working fine yesterday and last night our SSL was updated on the IIS site. Lietuvos bankas plėtoja – m. veiklos penkias strategines kryptis, aiškiai įvardijęs, ko siekia šiose prioritetinėse srityse.
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Let's assume it is 7 Ohm. Some RE is useful for linearity and thermal stability. Let's have one RE, only 1 Ohm. Now we have 6VDC over 8 Ohms. That means 9W DC power outtake from 12V in idle state. Constructions like this were used by hobbyists in the old days say - because they could get a couple of watts acceptable audio signal AC power without complex push-pull stages and the continuous power loss wasn't a problem if one used 12V car battery as his power supply.
A 20cm x 20cm x 4mm aluminium heatsink was able to keep the transistor cool enough. The price of the transistors and other components is today so low that it's useless to avoid the normal push-pull output stage. Even class A amp works best as push-pull. One trick : Put a massive inductor in parallel with the speaker. The DC current does not go through the speaker and you can multiple the output AC power, because the voltage swing can be more than 12Vpp.
The inductor should be about 50 mH or more and it's iron core should be large enough to stand the DC magnetization without getting saturated. In theory you can add a DC saturation compensating winding to the same inductor core if you drive the compensating DC through another speaker to pick the outputted AC.
Otherwise it's a shorted transformer. After watching those two videos, Single transistor, 1W and Adventures in a one transistor audio amplifier , I had to illustrate a slightly more sane design approach. To start out, here's the basic idea about how to drive a speaker without having to find and use a flux-limiting, gapped, audio transformer -- which you will definitely need if you plan to run DC current through the primary :.
Together, they can do a fair job of sinking and sourcing current. On the left, I've connected the speaker slightly differently which would also work fine in order to help segue into the transition on the right.
I've also added the 3rd BJT that's needed. On the right, I've bootstrapped the design to provide the current source indicated on the left. So it will form the equivalent of a constant current source. Just what we needed. The design is already taking shape. But it's time to put some parameters into it. NFB will be required to linearize the output and to set the AC gain. It will often be less, but this is safe.
But let's make it 10X bigger. So those values are set. As shown on the above schematic. You can see in the above schematic that I've added a few parts to achieve that. It was important in order to roll off the high frequencies.
So it's included now. I promised to add a class-AB. There are some tweaks needed to deal with discrete BJTs that haven't been included, nor discussions about them. So again, this is more of an educational level -- though if you built it I expect you'd still get passable results from it. Adjustments available for the VBE multiplier so that the quiescent current can be set up where you want it and so that the parabolic thermal response can be tweaked, as well. Happy Coding Pauwelyn Devendra Vaja Devendra Vaja 3, 1 1 gold badge 16 16 silver badges 13 13 bronze badges.
This is a very good answer. Our experience was similar though not the same. We made multiple tweaks along the same lines both on the client and the server. Our error rates have now reduced to about times less than they were before though they still haven't gone away.
I am facing same issue, my application developer using react native. So what to do in react native code to fix this issue? If using Nginx and getting a similar problem, then this might help: Scan your domain on this sslTesturl , and see if the connection is allowed for your device version.
Who said anything about Nginx? If the connection of a device were not allowed it wouldn't connect but that's not the problem - Rickster says: 'trying it multiple times somehow "fixes it" and we get a success'. Ohh, Yes, you're right. I mean if using Nginx and getting a similar error, then this would fix.
That triggered the problem. Went back to IIS, disabled the checkbox Problem Solved!!!! Hope this helps!!! Jon 6, 6 6 gold badges 41 41 silver badges 61 61 bronze badges. Jorge Navarro Jorge Navarro 81 1 1 silver badge 1 1 bronze badge. SSLHandshakeException: Handshake failed and this is fixed by adding the check for Android 7 particularly, like if android. Builder ConnectionSpec. Mykaelos Mykaelos 7 7 silver badges 6 6 bronze badges.
Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog. Podcast What can you program in just one tweet? Ciao Winter Bash ! So we can say:. Using calculus I'll avoid the details here , I'd instead just solve the following the negation is due to the fact that I know if the load current increases that the output voltage decreases :.
We'll analyze the first circuit and then we'll analyze the "Thevenin equivalent" circuit for both cases. So we'll have four results and we'll compare them. So this matches up with what we just calculated for the upper-left circuit.
So this matches up with what we just calculated for the lower-left circuit. I think you can see, at least from these examples anyway, that it appears this "trick" works.
The above assumes that the BJT is in active mode and isn't saturated by the circuit that surrounds it. But this is easy to test.
You treat Vcc as ground during resistance calculations, and determining the resistance of the circuit. Short independent voltage sources and open independent current sources. The equivalent DC source and its effective series resistance applied to the base is what they are calculating so, in the example in the first reference they calculate the voltage at the base under the assumption that the base takes no current 3 volts and, the effective series resistance of that 3 volts.
That effective series resistance is the parallel combination of R1 and R2. If you don't understand why that last part is so then that's a different question. Go study Norton's and Thevenin's theorem.
So, armed with the open circuit voltage of 3 volts and the effective series resistance of that source, you plug those numbers into the formula to calculate q-point: -.
Sign up to join this community. The best answers are voted up and rise to the top. Asked 1 year, 6 months ago. Active 9 months ago. Viewed times. I copy the relevant diagram and calculation for convenience below. Or are you done? So I may add something. Not sure when. Active Oldest Votes. Let's proceed Thevenin Voltage of a Resistor Divider A resistor voltage divider looks like this: simulate this circuit — Schematic created using CircuitLab On the left side we have two resistors in series between a power supply.
Let's add a load to the above circuit, as follows: simulate this circuit Note that I've drawn a box around our resistor divider circuit on the left side. I don't yet fully understand this - but it might be because I'm not yet fully awake. Sorry if it's a stupid question. Elliot Alderson Elliot Alderson Even than, I don't fully understand what that means, physically so to speak. Why do you say "set Vcc to zero" also? This is a very broad topic; too broad to address in these comments.