Video To Minus One Converter
Leida
I have a text file of invoiced and paid amounts that I'm manipulating and converting to an Excel file using Alteryx (which I'm new at). I'm having issues converting some of the fields from strings to numbers, in part because some of the numbers are negative and have a dash to the right (e.g. 5,371.58-). I've read some of the other posts on this sight, and tried using various combinations of "ToNumber" and "RegEx" formulas, but so far I've only succeeded in eliminating the negative sign, rather than converting the text string to a negative number. Any guidance would be appreciated.
I am also stuck with the problem you faced. Can you guide how were you able to convert the string to an integer/ double data type post bringing the minus from the end to the beginning? Whenever I change the data type using Select, it takes the first digit only.
Every now ad then I need a negative power supply with a reasonable power. At ebay a and aliexpress the LM2576 positive output buck converters modules are sold cheap see fig1 and according schematic depicted in figure 2. Schematic 3 is an example of a buck converter with a negative power output coning from the TI LM2576 data sheets.
I examend the two schematics and looked for the differences. I noticed that basically only the negative lead of the input capacitor has a different position between the two schematics. In fig2 it is connected to the ground and in fig3 to the output. From a module perspective the changes are that the output has changed label from output to ground, and the ground has changed label to negative output. Physically nothing has changed much except for then negative lead of the input capacitor.
Q2: If it is correct then I do have and other question. Why is the output current of the negative schematic fig3 0.7 A and not 3 Amp as it is for the positive buck power supply?. Can that be boosted somehow?
Depending on the equipment used by your provider, a lens prescription can come in either a plus (+) cylinder or minus (-) cylinder notation. Although the prescription form may vary, the optical properties of each lens remain the same. The optometric transposition calculator is a handy tool created to quickly transpose any prescription with ease. Simply input the correct lens formula and your prescription will automatically convert to the corresponding lens parameters.
I have a column with positive and negative numbers but I need all numbers without the minus. Is there any way to eliminate the minus? I thought about something like absolute value bars, but I havent found a way yet.
There are many applications that requireboth positive and negative DCvoltages generated from a single inputsupply. The LT3582 is a highly integrateddual switching regulator thatproduces positive and negative voltagesfor AMOLEDs, CCDs, op amps, andgeneral 5V and 12V supplies. TheLT3582 uses a novel control schemeresulting in low output voltage rippleand high conversion efficiency over awide load current range. The total solutionsize is very small due to the tiny3mm 3mm 16-pin QFN package, integratedfeedback resistors, integratedloop compensation networks and thesingle-inductor negative output topology(see Figure 1).
The power-up ramp rates of the outputvoltages are also adjustable. Slowlyramping the outputs (also known assoft-start) reduces what would otherwisebe high peak switching currentsduring start-up. Without soft-start,high start-up current is inherent inswitching regulators due to VOUT beingfar from its final value. The regulatortries to charge the output capacitors as quickly as possible, which resultsin large peak currents.
The output voltage ramp rates areproportional to the ramp rates of theRAMPP and RAMPN pin voltages. Uponchip enable, a programmable current(1A, 2A, 4A or 8A) linearly chargescapacitors (typically about 10nF)connected to the RAMPP and RAMPNpins. By varying the capacitor sizesor charging currents, a wide rangeof output voltage ramp rates can beaccommodated.
Smart control of the output disconnectPMOS also gives the LT3582 theunique ability to generate a smoothVOUTP voltage ramp starting fromground and continuing all the wayup to regulation (see Figures 6 and 8).This ability is not possible with typicalboost converters because the currentpath from VIN through the inductor(L1) and Schottky diode (D1) to theoutput prevents it from starting at 0V(see Figure 7).
The disconnect control circuitry inthe LT3582 allows VOUTP to discharge toground when disabled. Once enabled,the gate of the output disconnectPMOS is precisely controlled such thatVOUTP rises smoothly from ground upto regulation where the PMOS is fullyturned on to reduce power losses.
A default power-up configurationcan be made permanent in the LT3582through the One-Time-Programmablememory. The chip will always usethe default configuration from OTPmemory upon power-up. Unlesslocked by programming a specificOTP memory bit, the chip configurationcan be changed after power-upby writing new settings through theI2C interface.
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There is probably no greater single cause of lens error than the fact that physicians have never settled on a standard for writing prescriptions with either plus or minus cylinder values. It has been my experience that the majority of Optometrists use minus cylinder, while Ophthalmologists land fairly solidly in the plus camp. After all my years in the optical field, I have yet to hear any valid argument as to why a standard has never been agreed upon between the professions, but to use a tired cliche', I suppose it is what it is.
I am going to take this opportunity to throw my two cents worth into the argument for any Doctors that may be reading this. I prefer to work with minus cylinder for the following very common sense reason. When you write a prescription for spectacle lenses, that prescription is going to be used for one purpose, and that is to have glasses made. ALL spectacle lenses are made with minus cylinder. It does not make sense to me that you would generate a prescription knowing that at some point, someone, and perhaps multiple people are going to have to transcribe it. The door is being opened for mistakes to happen. If you would simply write the prescription in minus cylinder form to begin with, errors could be significantly reduced.
Ok, I am done picking on the doctors. The fact remains that we as Opticians are going to need to deal with both plus and minus cylinder prescriptions, and we should have a system in place to make sure that transcription errors do not occur. We all should know how to convert plus cylinder to minus. The conversion is as follows.
Add the sphere and cylinder values together algebraically taking the positive and negative signs into account. The result is your new sphere power. Now change the plus sign of the cylinder to a minus, and keep the cylinder power the same. Finally, change the axis by 90 degrees.
The most common transcription error is ending up with a lens that is 90 degrees off axis due to forgetting to adjust the axis parameter. When an Ophthalmic technician is preparing to edge a finished lens, the first step they perform is to verify the lens power and determine the axis alignment by placing the lens in a lensometer. The technician references the axis portion of the prescription first. If that number has been provided incorrectly, the result will be a spectacle lens that is 90 degrees off axis. So how can we avoid transcription errors?
Pay attention and always double check your transcriptions when you do them. My favorite way to avoid transcription errors is not to transcribe the prescription to begin with. When I get a prescription written in plus cylinder, I also order the lenses in plus cylinder. It is true, that someone at the wholesale lab probably has to transcribe it if their software doesn't do that for them, but that situation is out of my hands.
We will receive the lenses either uncut, or completely finished if our employer does not utilize onsite finishing. The invoice that accompanies the lenses will normally be written in minus cylinder since that is the way the lenses are made. My advice is to ignore the invoice prescription and use the prescribing doctor's original to verify the lens powers. If the lenses are to be edged in house, read the lenses in plus cylinder by setting the axis on your lensometer to match the axis on the doctor's original Rx, then set the power wheel to match the prescribed sphere power. Now simply rotate the lens by hand until the sphere power mires are clear and sharp. Lastly rotate the power wheel counterclockwise to verify the cylinder power. Dot your lenses, and you are ready to go with no off axis issues. If you use an autolensometer simply make sure it is set to plus cylinder.
The procedure for verifying lens powers for completely finished jobs is identical to what I described previously with the exception that it is impossible to rotate the lens by hand. If the lens has been cut and mounted off axis, it will become obvious when checked against the doctor's original Rx, as the lensometer mires will not focus with the lensometer set to the original prescribed powers. Mistakes from the wholesale lab will be caught in this manner, but only if the lenses are verified against the ORIGINAL doctor's prescription. If you verify against the lab invoice, the mistake will not be caught until the lenses are dispensed, and that is when the mistake becomes official.
Always check and double check and don't transcribe prescriptions any more than is absolutely necessary. Verify prescriptions in whatever form they are written in to begin with, and you will have by far fewer errors.
I have an automated Flow which imports space delimited text files sent via email, aggregates dollar figures from each line for an invoice total, then creates and emails a CSV file for import into another program. The data is simple, only six columns with no header, and looks like this:
4a15465005