Electronics > Projects, Designs, and Technical Stuff
High voltage safety and design considerations
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Zero999:
LTSpice doesn't add noise to plots, using the transient response mode. A separate noise simulation is required, which needs the models to reflect reality.

What slew rate, in terms of Amps per second, do you need? Does it need to work down to DC? Can you drive it via a transformer?
Someone:

--- Quote from: OM222O on June 26, 2019, 10:09:54 am ---Any suggestions regarding obtaining +-110V and what are safety issues that I should be concerned with high voltage DC applications?
--- End quote ---
As above, seriously consider bridged drive so you only need a single sided supply. Motor drives are somewhat similar and show examples of how to put current measurement in the feedback path all at happy low voltages. For a one off its usually cheaper to just buy off the shelf products, by the time you make a few mistakes and buy extra parts its easy to run through a budget.

100-150V at 25mA is just 5W, there are many suppliers of DC-DC supplies that will solve that, only consider building your own power supply if you plan to make 10,000 of them.  Safety is mostly about preventing people coming into contact with the 100V by adding appropriate insulation (all the way up to and possibly including the actuator).
OM222O:
We finally settled on 3 7s and one 4s LiPo packs for a voltage range of 105-80V. This will be doubled for the + and - rails. The problem with the birdge approach is the high part numbers, especially needing 2 op amps. The ADHV costs about 15$ a pop and I need 12 copies of that circuit. I think using batteries will be safe since they will be floating with respect to ground and low current fuses will prevent shorts or other issues from causing any major damage.
Zero999:

--- Quote from: OM222O on June 28, 2019, 08:55:15 pm ---We finally settled on 3 7s and one 4s LiPo packs for a voltage range of 105-80V. This will be doubled for the + and - rails. The problem with the birdge approach is the high part numbers, especially needing 2 op amps. The ADHV costs about 15$ a pop and I need 12 copies of that circuit. I think using batteries will be safe since they will be floating with respect to ground and low current fuses will prevent shorts or other issues from causing any major damage.

--- End quote ---
Then don't use the ADHV. Use ordinary, cheap op-amps, run off <30V and some discrete devices to amplify the output voltage.

Also note that it's very hard to protect semiconductors with fuses, normally the semiconductor blows first. Check that the fuse is rated for use with DC and that it has sufficient breaking capacity.
Someone:

--- Quote from: OM222O on June 28, 2019, 08:55:15 pm ---I think using batteries will be safe since they will be floating with respect to ground and low current fuses will prevent shorts or other issues from causing any major damage.
--- End quote ---
Until you get a short on their unfused side and then have 1kW or more fault to deal with. Batteries are much less safe than a current limited power supply here, you haven't discussed isolating the control signals or the actuator so the 100V supply will not be floating.


--- Quote from: OM222O on June 28, 2019, 08:55:15 pm ---The problem with the birdge approach is the high part numbers, especially needing 2 op amps.
--- End quote ---
You're in the range of operation where a H-bridge will likely work (I've never seen H-bridge used to describe a bridged linear amplifier). No linear mode devices, simple hard switching and a control loop.
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