Searching a cheap circuit that generates 15kV DC (to drive an artificial muscle) - Page 1
Forum section: electronics / projects

author: petert
author_rank: Regular Contributor
timestamp: August 17, 2020, 05:40:21 am
content: Hello,I'd like to replicate a research paper, that creates an artificial muscle out of an oil-filled plastic "bag", with electrodes on each side.It essentially acts as a capacitor: when charged the "muscle" contracts, due to the electrodes/"plates" being attracted to each other (I can provide more details if there is interest).My main issue is that this "muscle" needs a 15kV DC supply to drive it (and a way to control the voltage, like a power transistor), and the only options I found are around 300€+.Are there cheaper options, or open designs that I could build myself for relatively cheap?As this is for embedded use (such as in a robot), the PSU should be small.

author: Berni
author_rank: Super Contributor
timestamp: August 17, 2020, 06:35:06 am
content: If you never worked with high voltage then you are in for quite a learning curve with a fair share of casualties in the form of blown components or burnt wiring. If you don't know what you are doing thenDON'Tdo it. High voltage can become pretty dangerous in some cases.That being said the task may range from "an easy afternoon project" to a "2 year research project by a team of engineers" depending on how you exactly define your requirements. How small is considered small, what are the currents involved. how fast and precise does the output need to be controlled? Considering its capacitive does it also need 2 quadrant current operation?...etcThe easy way of getting HV DC in the 10s of kV is a flyback transformer from a CRT TV, but that's just one part of the story.

author: Gyro
author_rank: Super Contributor
timestamp: August 17, 2020, 12:26:59 pm
content: You could maybe try one of those cheap Chinese inverter 'spark generator PCBs', eg.https://www.ebay.co.uk/itm/High-Voltage-Inverter-Generator-Spark-Arc-Ignition-Coil-Module-DIY-Kit-15KV-3-7V/202951815011(they're available everywhere).The output of the coil is AC so would need to go through an EHT rectifier diode (unless your 'muscle' could also be persuaded to work on high frequency AC). Using one of these with a very low output capacitor value after the rectifier (hopefully the internal capacitance of the muscle would be sufficient).Being low voltage battery powered (don't try hooking it up to a mains powered PSU), the output would hopefully - but NOT GUARANTEED - to be in the hurts like hell but unlikely to kill you category. You would need lots of insulation - silicone sleeving and appropriate sealant for protection, and to avoid corona discharge, but it might just be workable. A high value, high voltage current limiting series resistor right at the output of the coil would help too.Control would need to be on the low voltage input of the inverter, using individual inverters for each muscle - there's no point in trying to switch the 15kV.You need to be very cautious and read up on HV precautions, but I can't immediately think of a cheap safer method. There are several YT videos around on these inverter modules which might give extra information on their operation and precautions.

author: KaneTW
author_rank: Frequent Contributor
timestamp: August 17, 2020, 12:44:22 pm
content: 300E for a 15kV PSU is a steal. Just measuring that voltage will require way more investment.