EEVblog #110 - Let's Design a DC to DC Switchmode Converter
Why Electrical Engineering Stack Exchange recommends it
Electronics Stack Exchange answerers point people to it as a practical, step-by-step introduction to the MC34063 when someone wants to build or understand a boost, buck or inverting converter.
Recommended by 6 people across 7 different months, 2011 to 2024.
What it is
Dave Jones of EEVblog walks through designing a DC-DC switchmode converter around the MC34063 chip, then builds it on the bench and measures its performance. It is a 37 minute hands-on tutorial aimed at people new to switching regulators.
What people said
Recommends steverino · 2015-01 · Electrical Engineering Stack Exchange · on “Convert a device that is powered by a 12V 2 amp ac-to-dc SMPS to a battery powered device”
Assuming you will still have automobiles in your off grid location; a very simple and cheap alternative is to buy one or two extra auto batteries. The car already has the voltage regulated charging system in place. And at a 2 amp draw, a typical car battery will run your device for quite awhile. Nevertheless, aside of offering an alternative, back to the question itself: 1 Yes it is possible. Even with building your own battery fed regulator, you have some options. You could make a battery pack that places several batteries in series til you have 3-5 volts above your rgulated output and use a cheap and simple linear regulator. Or you could build a switch mode power supply as you mention. 2 &
Recommends user59864 · 2015-10 · Electrical Engineering Stack Exchange · on “24V ceramic heater to work on 12V?”
You might as well use or build [this video] a DC-DC boost converter to double the voltage for your heater. David Jones explains it in details [LINK] on his video blog.
Recommends Maciej Kopeć · 2016-03 · Electrical Engineering Stack Exchange · on “Confusion with MC34063 Vsat”
When digging through the datasheet I stumbled upon the same problem. The datasheet gives the answer to your question. Look on page 9, down on the schematic. You can see that pins 1 and 8 are directly connected, consequently, if you look on page 5, table in point 7.6 you can see that test conditions for Darlington pair is when mentioned pins are directly connected. When you look closer at the internal schematic of the IC itself you will realize, that this connection makes Q1 and Q2 of the IC a Darlington pair. What I would do in such situation is take Vce(sat) of the Darlington connection to my calculations for inverting config, as long as you won't use external switch and hook up pins 1 and
Recommends Jeroen3 · 2019-12 · Electrical Engineering Stack Exchange · on “How do I really turn 3.7volts to 5 volts (simple explanation, please)”
Ever got that big voltage spike when de-energizing a relay without diode? A boost converter uses exactly that effect. Except instead of shorting this surge, it stores it in the capacitor. Controlled, many times a second. [LINK] I suggest you try to build one. Tip: MC34063 [LINK] Tutorial by EEVBlog [this video]
Recommends ErikR · 2021-05 · Electrical Engineering Stack Exchange · on “VREF and COMP pins for a UC3845”
If you want to experiment with a switching regulator, try the MC34063 -- it's like the 555 of the switching regulators, old but still widely used. You might even find one in a car USB charger adapter. You'll easily find video tutorials on it like (here) [LINK] and (here) [this video] , for instance.
Recommends MicroservicesOnDDD · 2021-10 · Electrical Engineering Stack Exchange · on “Best method for generating low current (5 - 10 mA) -2.5 V supply”
Your application is a good case for the inverting mode of the classic MC34063 switching regulator. Only 200mA saturation current is necessary, so a good, inexpensive inductor would be the $0.50 USD (at 1 qty) Bourns RLB0914-331KL 1.25A Sat, 330 µH Unshielded Wirewound Inductor [LINK] 740 mA, 760mOhm Max. Here are the design parameters: 1.4 Vsat output sw, 0.5 Vf diode, 5 Vin, -2.5 Vout, 4.2 Vin(min), 0.050 Iout, 24KHz Fmin, 0.01 Vripple(pp) [LINK] And here's the worked-out design: MC34063A design, Rsc=1.6 Ohm, L=330uH 200mA Sat. min., Ct=750pF, Cin=Cout=1000uF Low ESR, Vin=4.2v-6.0v, Vout=-2.5v, suggest the optional filter of 1uH + 100uF, R1=R2=4.7K Ohm [LINK] I did not verify the design (bu
Recommends MicroservicesOnDDD · 2024-05 · Electrical Engineering Stack Exchange · on “Is there a standardized process for Inductor selection calculation for boost LED controllers?”
Not a professional EE, just someone making a serious study of boost converters (and to a lesser extent, other kinds). So I may not be able to answer all of your questions. That said... I hope this is what you wanted. The following Datasheet of an MC34063A contains a limited example of what you seek, a formula based approach for use with design of boost converters, including inductor sizing. The following Digikey page contains a link to a datasheet containing the formulas. Multiple manufacturers make this chip, but some datasheets are better than others, so look over a few. I also like the Texas Instruments datasheet. 497-7849-2-ND at Digikey [LINK] STMicroelectronics MC34063ABD-TR Boost Form
Cites dren.dk · 2011-05 · Electrical Engineering Stack Exchange · on “What are some common/popular/go-to switching voltage regulators?”
That's easy, MC34063 [LINK] is a very common part that has been around for quite a while so there are several manufacturers and many applications. In the buck configuration it will output up to 700 mA without dissipating very much power. It comes in dip8 and soic8, so it's small enough for many products and still easy to prototype with. You can find lots on ebay [LINK] for very little money The only disadvantage is that it's an older part with a lower switch frequency than newer parts, so the inductor will have to be a bit larger. For space-critical applications you will probably need a newer part with a higher switching frequency, so the inductor can be smaller, but those parts are quite a
Cites Nathan Campos · 2013-07 · Electrical Engineering Stack Exchange · on “Choosing a Switchmode Converter for a Battery Powered Project”
I'm currently designing a battery powered, 2xAA in this case, project. The problem that I have is very simple, I want to power a DS1307 [LINK] (the only part in my circuit which requires 5V). I've looked into similar parts like the DS1337 [LINK] and the MCP7940 [LINK] , which operate under 3V, but they don't have a battery backup pin like the DS1307, which is something I want. So, the first thing that I thought was to build a step-up DC/DC converter circuit to power the RTC (that's the first thing I thought, so I'm open for suggestions). Since I never used a switchmode converter before I decided to watch Dave's video [this video] about the MC34063 [LINK] , but the problem with it is that its mini