The S7V8A switching step-up/step-down regulator efficiently produces an adjustable output between 2.5 V to 8 V from input voltages between 2.7 V and 11.8 V. Its ability to convert both higher and lower input voltages makes it useful for applications where the power supply voltage can vary greatly, as with batteries that start above but discharge below the regulated voltage. The compact (0.45″ × 0.65″) module has a typical efficiency of over 90% and can deliver 500 mA to 1 A across most combinations of input and output voltages. The Pololu step-up/step-down voltage regulator S7V8A is a switching regulator (also called a switched-mode power supply (SMPS) or DC-to-DC converter) that uses a buck-boost topology. It takes an input voltage from 2.7 V to 11.8 V and increases or decreases the voltage to a user-adjustable output between 2.5 V and 8 V with a typical efficiency of over 90%. The input voltage can be higher than, lower than, or equal to the set output voltage, and the voltage is regulated to achieve the set output voltage. This flexibility in input voltage is especially well-suited for battery-powered applications in which the battery voltage begins above the desired output voltage and drops below the target as the battery discharges. Without the typical restriction on the battery voltage staying above the required voltage throughout its life, new battery packs and form factors can be considered.
R**S
Good, exactly what I needed!
I've bought two now. The first I fried using too high input voltage because I just wanted to see what happened (expensive test) It failed closed -- perfect! That was good to know and made me more confident connecting this to my expensive Fatshark goggles. I used this to make my own voltage regulated extension cable for my FPV goggles. I use DIY Li-Ion packs and need a way to take them to lower voltage without the goggles shutting down (FatShark Users probably know the struggle) I aimed for around 8v but ended up a little below once I added the load...I left it alone and added a dab of hot glue to keep the adjustment screw in place and heat-shrinked the whole assembly. See the the picture below. I've included a nickel in the shot for size comparison....super small!
I**N
Excellent regulator for your voltage sensitive electronics project.
I am using this in a measurement buoy. This is a critical piece, since it balances out the power fluctuations of the solar and battery.During the day the solar panel pumps out 6.5 volts to the Teensy, GPS and satellite transceiver. At night when the battery takes over, the current drops to 4.2v - 3.7v.The Pololu voltage regulator keeps everything at 5.05v. You can manually set the voltage via the adjustment wheel. Make sure you use a plastic flathead screw driver, since a metal screw driver will throw the voltage off while it is in contact with the adjustment wheel making it difficult to get accurate readings on voltage.I have been testing benching it for a month now and the voltage has stayed at 5.05v for each test.
B**D
super good up-down regulator
This this is buck-boost so it ROCKS! Below 5v, above 5v, it doesn't matter, you get 5v out. great little regulator. I wish TI (the chip maker) made it take in a wider (higher) voltage range.
M**L
Awesome Product
Awesome product! Perfect for powering a circuit with a 9 Volt battery. I am using it to power a wide-band LNB I mounted in a box. The ability to vary the output voltage is a real plus. The extra small size (about a postage stamp) makes it easy to find a place to install it.
T**R
Polulu adjustable voltage regulator
I needed these little gems to push up voltage on a quadcopter I'm building which requires a strong tail servo and most servo's can operate above 6v. This is adjustable so I can set what ever voltage I need from 5v- 7v
T**S
Works Great
Running my Onion Omega2 off a battery, this thing works well.
C**N
Upgraded to 5 stars -- efficiency is higher than I initially thought
Update 2/19/2020 - I decided to do an actual use experiment to test efficiency in which I fully charged four 18650's in parallel with my Tenergy charger. Then I used the Pololu S748A to operate a string of 50 fairy light LED's with measured current draw at 40.66 mA, keeping track of on time. After the pack was drained to 3.15VDC (empty), I recharged it with the Tenergy charger tracking 9731 mAh to complete the charge. The total run time was 212.25 hours. So from the perspective of mAh stored in the cells to mAh actually utilized by the lights, the regulator was 88.7% efficient (40.66 mAh used versus 45.85 supplied to the regulator). All of the various battery packs I've tested this way to date are much lower in efficiency (~60%), so I have to upgrade this little device to 5 stars.==================Based upon the efficiency curves on Polou's website and their Amazon product description, I was expecting power efficiency in the range of 90% and at least over 80%. Using my bench power supply and my multimeter for voltage and amperage measurements with 4.00 Vin and 2.8 Vout, at output current levels of 30, 150 and 200 mA, I got VAout / VAin percentages of less than 80%, averaging around 75% power in to power out. I'll use it in my LED application and see how it performs with 18650's versus the set-up I've been using and may change the rating depending upon results.======================Update: After running my LED application for a few days and comparing consumption data with my previous set up, it's clear this device is far superior too what I'd been using and so I ordered a second one. With that I have increased my rating to 4-stars, but less than five because my measured efficiency results fall a bit below those shown on the Polou site charts. I believe the device is the TI TPS63060DSC QUJ with pin 4 PS/SYNC clamped low (power save off) and this would account for the efficiency slightly under 80% at low voltage and low output current. Still quite good overall.
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