CyberBrite
Junior Member level 3
wiring diagram pegeot 405sr
Hi All,
I want to control my DC motor blower speed. The motor blower have 15 amperes current maximum in high speed at about 12.5 Vdc from lead acid battery voltage.
I found from internet a darlington circuit configuration for motor speed control using Q1 BFY51 (NPN) and Q2 TIP32C (PNP), and because I want to control current flow to motor blower upto 15 amperes then I replace Q1 with Motorola MJ15003 (NPN) and Q2 with Motorola MJ15004 (PNP).
From MJ15004 & MJ15003 darlington-pair transistor datasheet (PDF-attached) I get information they both have collector current upto 20 amperes and cause this I use them to replace Q1 and Q2, but I get overheat in transistor Q2 and worried it can damage, and now with my simple-thinking I plan to add one more transistor MJ15004 as Q3 as shown in circuit diagram attached. I don't know what if this circuit working finaly and need some helps from you about this.
The variable transistor is potensiometer from control speed knob at my car's dashboard, we can not change this potensiometer because it integrated with the others control knob.
And the relay normaly open used for overload-current protection that by pass from Vss (battery) into motor when speed knob turn on maximum (potensimeter at 0 ohm) to make transistor Q2 doesn't work hardly at highest speed.
And when speed knob turn into minimum (potensiometer resistance rise up through to 3.8 Kohm maximum) the current flow pass to relay's wirecoil into base terminal Q1 is shrinking too and at about less then 130 mA relay is open (cut off) again and motor blower get current drive from Q2 back again.
Now, I hope any body could help and give me suggestions about this circuit diagram. Is this circuit diagram working perfectly to control motor blower speed from stop to high speed ? Please give me your corrections, suggestions, advices or responses.
And sorry if my english words are badly.
Thanks in advance.
Hi All,
I want to control my DC motor blower speed. The motor blower have 15 amperes current maximum in high speed at about 12.5 Vdc from lead acid battery voltage.
I found from internet a darlington circuit configuration for motor speed control using Q1 BFY51 (NPN) and Q2 TIP32C (PNP), and because I want to control current flow to motor blower upto 15 amperes then I replace Q1 with Motorola MJ15003 (NPN) and Q2 with Motorola MJ15004 (PNP).
From MJ15004 & MJ15003 darlington-pair transistor datasheet (PDF-attached) I get information they both have collector current upto 20 amperes and cause this I use them to replace Q1 and Q2, but I get overheat in transistor Q2 and worried it can damage, and now with my simple-thinking I plan to add one more transistor MJ15004 as Q3 as shown in circuit diagram attached. I don't know what if this circuit working finaly and need some helps from you about this.
The variable transistor is potensiometer from control speed knob at my car's dashboard, we can not change this potensiometer because it integrated with the others control knob.
And the relay normaly open used for overload-current protection that by pass from Vss (battery) into motor when speed knob turn on maximum (potensimeter at 0 ohm) to make transistor Q2 doesn't work hardly at highest speed.
And when speed knob turn into minimum (potensiometer resistance rise up through to 3.8 Kohm maximum) the current flow pass to relay's wirecoil into base terminal Q1 is shrinking too and at about less then 130 mA relay is open (cut off) again and motor blower get current drive from Q2 back again.
Now, I hope any body could help and give me suggestions about this circuit diagram. Is this circuit diagram working perfectly to control motor blower speed from stop to high speed ? Please give me your corrections, suggestions, advices or responses.
And sorry if my english words are badly.
Thanks in advance.