Recent content by kjnhu

I don't think I see the figure you are referring to, do you happen to have the link for the datasheet you are using? I am using one from Nat'l Semi and either do not have that figure, or am misinterpreting what you are saying. I want to power my DVM from a 9V battery, but would like the LM317...

Hopefully this is one of the last questions I have to beg off of you, but I am unsure about using the LM317. I do not see the purpose of the Vin pin. If for example I want to make a 5V source, would it work for R1 to be 330 ohms and R2 to be 1000 ohms, would I get 5V out regardless of the...

Thank you once again berkeman, you have been an immense help. One more question (for now :D ) - I need a MOSFET like IRF150 with a maximum of Vth of 4V, but that one seems kinda pricy, as in $2-3 for each FET, do you know of a cheaper alternative?

One more thing, I haven't really covered anything in classes regarding voltage regulators, but would like to use the LM317 or LM117 in my circuit. I want to use it in two separate applications, one as a floating source generating 5V over a signal called "b", which is my low input to the DVM...

1. In this case, could I simply connect my op-amp that is operating at its rails to generate +-8V or so depending on if the +input or the -input is higher and connect it's output to the base of my transistor, connect 5V to the collector and connect my load then ground to the emitter...

1. Hmmm I am not sure what you mean by "buffer the opamp outputs with transistors to get current or voltage gain". How exactly would I connect a transistor to source the current but maintain the 5V signal? I am assuming for this I would use a BJT to provide current gain? But I am not sure how...

Thank you for the help berkeman. 1. I may be misreading the datasheets for the op-amps/comparitors I have been looking at, but can they only source about 50-60mA current? If this is the case, do I need to use a pullup resistor or something similar in order to source the current I need to...

I posted this on anther forum but it seems less active, so ill post it again here, hopefully that isn't violating any rules, if it is please let me know, but I really need to know what part numbers these components could be so that I can build this project. Could someone please recommend part...

last year (my soph year) i did a bunch of interviewing for coops/internships and got offered a couple so hopefully i can be of a little help. here are some typical questions i got asked: have you ever been working in a group where someone wasnt helping the group like they should, and if so...

Could someone please recommend part values for the following components, or tell me if they do not exist: 1. differential op-amp that can source enough current to turn on a BJT and an LED, and also outputs a voltage near the +-5V inputs 2. a BJT that can withstand up to 2V across it 3. An LED...

Thank you berkeman, that clears that part of my question up. My input would then be a differential input, so are you saying I need to connect COM to the average of the two inputs? Thank you again, Kevin

Thank you a million! I have emailed Intersil support about five times and not received anywhere near the quality of response that you provided me with. So since INHI and INLO can be floating with respect to the power supply for the chip, if I connect RefLo to my INLO pin, and then connect a 2V...

I am building an autoranging digital voltmeter as the subject line suggests and am having a problem with the ICL7107 chip that I am using. Looking at figure 15 on: http://www.intersil.com/data/fn/fn3082.pdf specifically RefHI and RefLO, with a 2V max input difference between the pos and neg...

I am building an autoranging digital voltmeter as the subject line suggests and am having a problem with the ICL7107 chip that I am using. Looking at figure 15 on: http://www.intersil.com/data/fn/fn3082.pdf specifically RefHI and RefLO, with a 2V max input difference between the pos and neg...