- Joined
- Apr 1, 2011
- Messages
- 15,183
- Helped
- 2,900
- Reputation
- 5,812
- Reaction score
- 2,982
- Trophy points
- 1,393
- Location
- Minneapolis, Minnesota, USA
- Activity points
- 113,743
is it a circuit of charge pump relay drive circuit?
actually i want to operate my relay with the charge pump relay drive technique (for UL safety standard)? can you suggest me any other circuit which can perform charge pump action to drive relay?
i am interested to operate 24VDC relay with this charge pump circuit, Part number of relay is T7CS5D-24, could you suggest me the value of other components?
* DC supply can be between 28 and 32 V.
* The zeners should each be rated for 50 to 65 percent of supply V. Together they must add up to more than the supply V.
(If the combined zener V is too low then it will allow unintended bias to flow from the PNP down through the NPN. This will turn on both transistors simultaneously and cause a short circuit.)
* The clock must alternate between sufficiently high V and sufficiently low V (near the DC supply levels), in order to bias the transistors properly.
* The device providing the clock signal must be able to both source and sink current.
1) DC supply must be the same as operating voltage of DC relay, is that true? so in my case i want to drive 24VDC relay
2) so according to that DZ1 and DZ2 should be around 18VDC or so ?
3) can you suggest me part no. of transistors,A1,A2 which is best suitable in this circuit?
4) please let me know the value of other component if you can that would be great help for me
and one more thing could you please suggest me the name of free simulation tool for transistor and Op-amp circuit?
Here is a revised layout.
The circuit doesn't meet the requirements for fail-safe operation achieved in the original circuit. A push-pull driver with e.g. 30 V swing will be required.
following are the condition where relay should not operate
1) when microcontroller fails
2) When microcontroller I/O pin goes in continous high stage
3) When microcontroller software gone hang or something wrong with software
4) when short circuit happen in relay drive section or related parts
Actually i got the information from UL that if we can control the relay with the help of charge pump concept we can satisfy above conditions, but i dont know how to develop a charge pump relay drive circuit.
Hello i am unable to simulate following circuit on falstad, can you please help me to identify the problem? suggest me if is there any thing wrong with circuit it self
I re-arranged wires so the simulator could recognize nodes correctly. I removed overlaps in the wiring.
The link below shows how the relay stays closed as long as the mosfet receives clock pulses. In that respect it operates as you intended.
However the relay will remain energized if the mosfet fails as a short-circuit. The relay is supposed to open if anything goes wrong. In this respect your new circuit apparently does not meet the fail-safe specs.
https://www.falstad.com/circuit/#$+...+12.0+12.0+0.0+0.5 o+0+64+0+35+40.0+6.4+0+-1
It has become clear why the UL recommends that your relay driver use a charge-pump. The idea is that the capacitors will respond to AC, but will not pass DC. Hence the AC must continue operating, or the relay loses power.
Thanks for rearranging the wires, i have seen the simulation but why other relay is not opearting at all (downword relay) ?
Whats the diffrent between Post 34 and Post 29(1st circuit) charge pump circuit?
Could you please guide me which one is more suitable as per fail safe standard and UL criteria?
Why we are using 28VDC to operate 24VDC relay (Post 29 1st circuit)?
Can we design such circuit which is operating on 24VDC power supply to drive 24VDC relay ? if its possible in our current circuit (Post 29 1st circuit), can you modify and share falstad link with me?
And if i want to operate 12VDC relay by 24VDC power supply sources, what are the necessary changes needs to be done in Post 29 1st circuit ?
Please let me know the part number of Post 29 1st circuit, so i can implement that circuit on bread board and check it practically.
I really appreciate your help....
Thanks for rearranging the wires, i have seen the simulation but why other relay is not opearting at all (downword relay) ?
Whats the diffrent between Post 34 and Post 29(1st circuit) charge pump circuit?
Could you please guide me which one is more suitable as per fail safe standard and UL criteria?
Why we are using 28VDC to operate 24VDC relay (Post 29 1st circuit)?
Can we design such circuit which is operating on 24VDC power supply to drive 24VDC relay ? if its possible in our current circuit (Post 29 1st circuit), can you modify and share falstad link with me?
And if i want to operate 12VDC relay by 24VDC power supply sources, what are the necessary changes needs to be done in Post 29 1st circuit ?
Please let me know the part number of Post 29 1st circuit, so i can implement that circuit on bread board and check it practically.
I really appreciate your help....
Thanks for rearranging the wires, i have seen the simulation but why other relay is not opearting at all (downword relay) ?
Whats the diffrent between Post 34 and Post 29(1st circuit) charge pump circuit?
Could you please guide me which one is more suitable as per fail safe standard and UL criteria?
Why we are using 28VDC to operate 24VDC relay (Post 29 1st circuit)?
Can we design such circuit which is operating on 24VDC power supply to drive 24VDC relay ? if its possible in our current circuit (Post 29 1st circuit), can you modify and share falstad link with me?
And if i want to operate 12VDC relay by 24VDC power supply sources, what are the necessary changes needs to be done in Post 29 1st circuit ?
Please let me know the part number of Post 29 1st circuit, so i can implement that circuit on bread board and check it practically.
Can you please let me know whats wrong with other relay circuit? Whats the logic to connect 2 relay with One MOSFET and Transistor?
Even personally i feel that Post #1 circuit is more perfect as per UL standard, but i am unable to identify specific Op-amp part number, could you please create Post #1 circuit in Falstad simulator? and yes i am going to control boiler by this Charge Pump circuit, thats why UL standard is mandatory.
I want to drive 24VDC relay with 24VDC power supply, how can i do that? because i have only 24VDC and 24VAC power supply available in my module, and i cant accomodate another 28VDC power supply.
Can you post a Falsatd simulator circuit which has 12VDC relay and it operates on 24VDC power supply?
And one more thing i am looking for a transformerless solution which can convert 24VAC into 24VDC, do you have any idea about that? any suggestion
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?